Merge pull request 'Keep disabled controls in the accessibility tree so their reason is announced' (#49) from fix/disabled-control-accessibility into main

Reviewed-on: #49

.gitea/workflows/build-app-preview.yml

@@ -43,7 +43,18 @@ name: Build App (Preview)
 # prunes previous previews itself, keeping the newest few. Bundles are ~130 MB a
 # release; the point of a preview is the build you are testing now.
 #
-# `sync-release.yml` is workflow_dispatch-only, so nothing here reaches GitHub.
+# A preview release is not meant to reach GitHub. `build-app.yml`'s inline
+# mirror never sees one (it only runs for its own `push`-triggered release),
+# but `backfill-releases.yml` pulls every Gitea release unfiltered and would
+# faithfully forward a preview's `prerelease: true` if it were ever dispatched
+# while one existed — so `GitHubRelease::prerelease` in `update_commands.rs`
+# is real defence, not a no-op, even though the `preview-<sha>` tag shape
+# (never valid semver) already blocks it independently. (The previous
+# mechanism here, `sync-release.yml`, was `workflow_dispatch`-only and read
+# `gitea.event.release.*` fields that are only ever populated by a `release`
+# trigger, so it could never have actually run; deleted rather than fixed,
+# since build-app.yml's inline mirror already does what it was meant to do
+# for real releases. See triple-c#32.)
 
 env:
   GITEA_URL: ${{ gitea.server_url }}
@@ -70,12 +81,23 @@ jobs:
     outputs:
       version: ${{ steps.version.outputs.VERSION }}
       sha: ${{ steps.version.outputs.SHA }}
+      # Everything after the first `-` in VERSION (e.g. `preview.a1b2c3d`).
+      # The bundle version fields never see this — see "Set app version" in
+      # each build job — but it is baked into the binary as
+      # `TRIPLE_C_BUILD_SUFFIX` so `get_app_version()` can still report it.
+      # An installed preview otherwise reports the same bare number a
+      # production build would, indistinguishable in the About panel and to
+      # `check_for_updates`. See triple-c#32.
+      suffix: ${{ steps.version.outputs.SUFFIX }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
+      - name: Fetch all tags
+        run: git fetch --tags
+
       - name: Compute preview version
         id: version
         run: |
@@ -86,21 +108,60 @@ jobs:
           # is testing and not something to hang a tag on.
           echo "SHA=$(git rev-parse HEAD)" >> $GITHUB_OUTPUT
 
-          # The patch number is computed exactly as build-app.yml does it, so a
-          # preview is labelled with the version the release it previews would
-          # carry. This used to be hard-coded `.0`, which made every preview
-          # installer claim to be x.y.0 no matter what it contained.
-          LATEST_TAG=$(git tag -l "v${MAJOR_MINOR}.*" --sort=-v:refname | grep -E "^v${MAJOR_MINOR}\.[0-9]+$" | head -1 || true)
-          if [ -n "$LATEST_TAG" ]; then
-            PATCH=$(git rev-list --count "${LATEST_TAG}..HEAD")
-            echo "Latest matching tag: ${LATEST_TAG} (+${PATCH} commits)"
+          # The patch number must be the same "one past the highest patch
+          # already used" build-app.yml computes for a real release — not a
+          # distance from the latest tag. It used to be
+          # `git rev-list --count <latest tag>..HEAD`, which build-app.yml's
+          # own history section documents as broken for exactly this reason:
+          # it resets to zero on every tag cut, so previews went *backwards*
+          # (0.4.62 -> 0.4.0) the moment a release landed, and nothing stopped
+          # a preview number from later colliding with a real release's.
+          #
+          # Reading the same `v${MAJOR_MINOR}.*` tags (including the `-mac`
+          # / `-win` suffixed ones a partially-published release can leave
+          # behind) means a preview built right before a release computes the
+          # exact number that release is about to take — e.g. `0.4.13` for
+          # both. That makes the two numerically *equal*, not "preview less
+          # than release" — plain semver ordering does not make a
+          # `-preview.<sha>` suffix sort lower on its own here, because
+          # `check_for_updates` compares against the bare, stripped
+          # `CARGO_PKG_VERSION`, never the suffixed display string. What
+          # closes the loop is `update_commands.rs`'s `is_preview_build`
+          # check, which relaxes that one comparison to `>=` specifically so
+          # "a release exists at my own number" reads as an update. See
+          # triple-c#32.
+          HIGHEST=$(git tag -l "v${MAJOR_MINOR}.*" \
+            | grep -E "^v${MAJOR_MINOR}\.[0-9]+(-mac|-win)?$" \
+            | sed -E "s/^v${MAJOR_MINOR}\.([0-9]+).*/\1/" \
+            | sort -n | tail -1 || true)
+
+          # Mirrors build-app.yml's own `EXISTING` guard: this workflow is
+          # also `workflow_dispatch`-able on `main`, not just PR-triggered, so
+          # HEAD can be a commit a release was already cut from. Without this,
+          # dispatching a preview there would compute `HIGHEST + 1` — one past
+          # that release — and produce exactly the "preview outranks
+          # production" failure triple-c#32 was filed over, just reintroduced
+          # through the manual-dispatch door instead of the automatic one.
+          EXISTING=$(git tag --points-at HEAD \
+            | grep -E "^v${MAJOR_MINOR}\.[0-9]+$" \
+            | sed -E "s/^v${MAJOR_MINOR}\.([0-9]+)$/\1/" \
+            | sort -n | tail -1 || true)
+
+          if [ -n "$EXISTING" ]; then
+            echo "HEAD is already tagged v${MAJOR_MINOR}.${EXISTING} — matching it"
+            PATCH="${EXISTING}"
+          elif [ -n "$HIGHEST" ]; then
+            echo "Highest patch already used on this line: ${HIGHEST}"
+            PATCH=$((HIGHEST + 1))
           else
             echo "No v${MAJOR_MINOR}.* tag yet — starting this line at .0"
             PATCH=0
           fi
 
-          VERSION="${MAJOR_MINOR}.${PATCH}-preview.${SHORT_SHA}"
+          SUFFIX="preview.${SHORT_SHA}"
+          VERSION="${MAJOR_MINOR}.${PATCH}-${SUFFIX}"
           echo "VERSION=${VERSION}" >> $GITHUB_OUTPUT
+          echo "SUFFIX=${SUFFIX}" >> $GITHUB_OUTPUT
           echo "Computed preview version: ${VERSION}"
 
   # One release, created once. The three build jobs run concurrently, so
@@ -249,6 +310,13 @@ jobs:
 
       - name: Build Tauri app
         working-directory: ./app
+        env:
+          # Baked into the binary via `option_env!` in `get_app_version()` —
+          # the bundle version above stays bare (WiX/MSI's ProductVersion has
+          # no room for a suffix), so this is the only place a preview build
+          # can still tell itself apart from a production one. See
+          # triple-c#32.
+          TRIPLE_C_BUILD_SUFFIX: ${{ needs.compute-version.outputs.suffix }}
         run: |
           export PATH="$HOME/.cargo/bin:$PATH"
           npx tauri build
@@ -361,6 +429,9 @@ jobs:
 
       - name: Build Tauri app (universal)
         working-directory: ./app
+        env:
+          # See the matching comment on the Linux job's "Build Tauri app" step.
+          TRIPLE_C_BUILD_SUFFIX: ${{ needs.compute-version.outputs.suffix }}
         run: |
           export PATH="$HOME/.cargo/bin:$PATH"
           npx tauri build --target universal-apple-darwin
@@ -489,6 +560,8 @@ jobs:
         working-directory: ./app
         env:
           TAURI_CONFIG: "{\"build\":{\"beforeBuildCommand\":\"\"}}"
+          # See the matching comment on the Linux job's "Build Tauri app" step.
+          TRIPLE_C_BUILD_SUFFIX: ${{ needs.compute-version.outputs.suffix }}
         run: |
           set "PATH=%USERPROFILE%\.cargo\bin;C:\Program Files\nodejs;%PATH%"
           cargo tauri build

.gitea/workflows/secret-scan.yml

@@ -0,0 +1,32 @@
+name: Secret Scan
+
+# **No `paths:` filter, deliberately.** The credential this exists for lived in
+# `app/src-tauri/src/docker/container.rs`, which `build.yml` would have skipped —
+# that workflow only runs for `container/**`. A scan that can be avoided by
+# touching the wrong directory is not a scan.
+#
+# This is the half of the check that nobody can bypass. The pre-commit hook in
+# `.githooks/` is faster and friendlier, but it is opt-in per clone and
+# `--no-verify` skips it; both are true of every git hook and neither is fixable
+# from inside a repository.
+
+on:
+  push:
+    branches: ["**"]
+  pull_request:
+    branches: ["**"]
+
+jobs:
+  scan:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      # The whole tracked tree, not just the diff. Scanning a range is cheaper
+      # but depends on getting the range right across pushes, force-pushes,
+      # merges and PR events — and a wrong range fails *open*. The full scan
+      # takes under half a second on this repository and cannot be evaded by
+      # arranging for the interesting commit to sit outside the window.
+      - name: Scan tracked files for credentials
+        run: sh scripts/scan-secrets.sh --tracked

.gitea/workflows/sync-release.yml

@@ -1,59 +0,0 @@
-name: Sync Release to GitHub
-
-on:
-  workflow_dispatch:
-
-jobs:
-  sync-release:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Mirror release to GitHub
-        env:
-          GH_PAT: ${{ secrets.GH_PAT }}
-          GITHUB_REPO: shadowdao/triple-c
-          RELEASE_TAG: ${{ gitea.event.release.tag_name }}
-          RELEASE_NAME: ${{ gitea.event.release.name }}
-          RELEASE_BODY: ${{ gitea.event.release.body }}
-          IS_PRERELEASE: ${{ gitea.event.release.prerelease }}
-          IS_DRAFT: ${{ gitea.event.release.draft }}
-        run: |
-          set -e
-
-          echo "==> Creating release $RELEASE_TAG on GitHub..."
-
-          RESPONSE=$(curl -sf -X POST \
-            -H "Authorization: Bearer $GH_PAT" \
-            -H "Accept: application/vnd.github+json" \
-            -H "Content-Type: application/json" \
-            https://api.github.com/repos/$GITHUB_REPO/releases \
-            -d "{
-              \"tag_name\": \"$RELEASE_TAG\",
-              \"name\": \"$RELEASE_NAME\",
-              \"body\": $(echo "$RELEASE_BODY" | jq -Rs .),
-              \"draft\": $IS_DRAFT,
-              \"prerelease\": $IS_PRERELEASE
-            }")
-
-          UPLOAD_URL=$(echo "$RESPONSE" | jq -r '.upload_url' | sed 's/{?name,label}//')
-          echo "Release created. Upload URL: $UPLOAD_URL"
-
-          echo '${{ toJSON(gitea.event.release.assets) }}' | jq -c '.[]' | while read asset; do
-            ASSET_NAME=$(echo "$asset" | jq -r '.name')
-            ASSET_URL=$(echo "$asset" | jq -r '.browser_download_url')
-
-            echo "==> Downloading asset: $ASSET_NAME"
-            curl -sfL -o "/tmp/$ASSET_NAME" "$ASSET_URL"
-
-            echo "==> Uploading $ASSET_NAME to GitHub..."
-            ENCODED_NAME=$(python3 -c "import urllib.parse, sys; print(urllib.parse.quote(sys.argv[1]))" "$ASSET_NAME")
-            curl -sf -X POST \
-              -H "Authorization: Bearer $GH_PAT" \
-              -H "Accept: application/vnd.github+json" \
-              -H "Content-Type: application/octet-stream" \
-              --data-binary "@/tmp/$ASSET_NAME" \
-              "$UPLOAD_URL?name=$ENCODED_NAME"
-
-            echo "  Uploaded: $ASSET_NAME"
-          done
-
-          echo "==> Release sync complete."

.githooks/pre-commit

@@ -0,0 +1,14 @@
+#!/bin/sh
+# Refuse a commit that adds something shaped like a live credential.
+#
+# Installed by pointing git at this directory:
+#
+#     git config core.hooksPath .githooks
+#
+# which `npm run hooks` in app/ does for you. It is per-clone — git will not let
+# a repository configure its own hooks path, for the obvious reason that cloning
+# a repo would then be enough to run its code. So this is opt-in on every
+# machine, `--no-verify` skips it, and neither of those is a flaw to fix here:
+# the CI job in `.gitea/workflows/build.yml` is the half nobody can bypass. The
+# hook exists to tell you in one second rather than in five minutes.
+exec "$(git rev-parse --show-toplevel)/scripts/scan-secrets.sh" --staged

CLAUDE.md

@@ -79,23 +79,34 @@ docker exec stdout → tokio task → emit("terminal-output-{sessionId}") → li
 - **`components/projects/home/`** — **Project Home**, the main-area view for a project:
   Overview / Sessions / Automation / Config / Files. Per-project configuration lives here, not in
   modals — see "UI conventions" below.
-  - **Files is container-side only. It does no host filesystem I/O, and must not grow any.**
-    The tab lists, opens (text and image viewer), renames and creates folders *inside* the
-    container: `list_container_files`, `read_container_file`, `rename_container_path`,
-    `create_container_directory`. There is no upload button, no "Save to host…", and no
-    drop-into-the-pane. Four successive audits found that host filesystem paths crossing IPC
-    were where the criticals lived — a caller-named host destination for container-controlled
-    bytes, an arbitrary host source read into the container, a `link(2)` upload reservation
-    that succeeded against a directory and failed forever on any filesystem without hard
-    links — so the feature was narrowed rather than fixed a fifth time. If a host path ever
-    needs to reach this pane again, the honest shape is for the *backend* to drive
-    `tauri-plugin-dialog`, so no host path arrives over IPC at all.
-  - **A file gets *in* by being dropped on the Terminal, and *out* through "Back up
-    container".** Those two are the whole host↔container story, they predate the Files work,
-    and their hardening is not to be weakened. `TerminalView`'s `onDragDropEvent` is Tauri's
-    native drop event (window-wide, so routed by `lib/dropTarget.ts` — geometry for *whose*
-    drop it is, a document-wide `dropIsBlocked` for whether the app should accept one at all;
-    keep both halves and keep `PaneVisibility`). Backup is
+  - **The Files pane's host transfers open their dialog from Rust, and that is the whole
+    design — do not move it back into the webview.** The tab browses, views (text and image),
+    renames and creates folders inside the container (`list_container_files`,
+    `read_container_file`, `rename_container_path`, `create_container_directory`), and it
+    copies single files in and out (`upload_files_to_container`, `download_container_file`).
+    The second pair call `pick_files_to_upload` / `pick_save_path`, which drive
+    `tauri-plugin-dialog` from the *backend*: the webview can ask for a picker and that is the
+    entirety of its influence — it cannot name a host path as an *input*. The claim stops
+    there and should not be widened: host paths still travel outward in error text, canonical
+    ones included. What is closed is the direction that produced the criticals.
+    That shape is not decoration. Four successive audits found that host filesystem paths
+    crossing IPC were where the criticals lived — a caller-named host destination for
+    container-controlled bytes, an arbitrary host source read into the container, a `link(2)`
+    upload reservation that succeeded against a directory and failed forever on any filesystem
+    without hard links. The feature was removed rather than fixed a fifth time, and it came
+    back only in the shape that removes the class: a frontend-driven dialog handing Rust a
+    string is the exact thing that failed, so re-introducing `open()`/`save()` in `FilesTab`
+    would undo the whole point while looking like a simplification.
+    None of the reservation machinery came back with it. There is no destination reservation,
+    no placeholder rollback and no collision marker — the OS save dialog already asks about
+    overwriting, and Docker's archive extractor overwrites on upload the way `cp` does.
+  - **Drag-and-drop is still not it.** There is no drop-into-the-Files-pane and no OS
+    drag-out; the buttons are the gesture. A file also gets *in* by being dropped on the
+    Terminal, and a whole tree comes *out* through "Back up container" — those two predate the
+    Files work and their hardening is not to be weakened. `TerminalView`'s `onDragDropEvent`
+    is Tauri's native drop event (window-wide, so routed by `lib/dropTarget.ts` — geometry for
+    *whose* drop it is, a document-wide `dropIsBlocked` for whether the app should accept one
+    at all; keep both halves and keep `PaneVisibility`). Backup is
     `file_commands::download_container_backup`.
   - **`resolve_host_path` applies the full lexical predicate twice — as written, and again
     after canonicalisation.** That includes the general hidden-component rule, which
@@ -103,8 +114,12 @@ docker exec stdout → tokio task → emit("terminal-output-{sessionId}") → li
     `~/.local/share` is refused. Do not narrow it back to a list of "credential" directories.
     That was tried, and allow-by-omission let `~/.local/bin` (write there and you own the
     user's next shell command), `~/.password-store`, browser profiles and `~/.pki/nssdb`
-    through a planted symlink with a perfectly visible name. The two callers left are
-    occasional, so over-refusing is the cheaper mistake.
+    through a planted symlink with a perfectly visible name. Over-refusing is the cheaper
+    mistake. Note the cost is real and has grown: of the four callers, the Files pane's two
+    are routine, and their path comes from a dialog — so an over-catch refuses a destination a
+    person actually chose (`~/.config` is the common one). Accepted, and not a reason to
+    narrow the rule, because the terminal drop and `download_container_backup` still take
+    their host path over IPC and this predicate is their only boundary.
   - **OS drag-out is not here.** `tauri-plugin-drag`, `stage_container_file_for_drag` and its
     host staging directory were held back for separate hardening and live on
     `hold/disk-and-dragout`. Do not re-add `drag:allow-start-drag` or a staging command
@@ -510,6 +525,178 @@ Anthropic and Bedrock deliberately keep Claude Code's own defaults.
   `models/project.rs` for anything that should default to true.
 - Cross-platform paths: Docker socket is `/var/run/docker.sock` on Linux/macOS, `//./pipe/docker_engine` on Windows
 
+## Secrets
+
+**`scripts/scan-secrets.sh` refuses a commit that adds something shaped like a live
+credential.** Enable the hook once per clone with `npm run hooks` (from `app/`), which sets
+`core.hooksPath` to `.githooks`. A repository cannot configure its own hooks path — cloning it
+would then be enough to run its code — so this is opt-in everywhere, and `--no-verify` skips it.
+The `Secret Scan` workflow is the half nobody can bypass; it carries **no `paths:` filter**, on
+purpose, because the incident that prompted all this lived in `app/**` and `build.yml` only runs
+for `container/**`.
+
+Three rules, and the second half of the third is what keeps it usable: vendor-prefixed tokens
+(`ghp_`, `sk-`, `AKIA`, `xox`, …), `BEGIN … PRIVATE KEY` blocks, and an opaque literal assigned to
+a secret-shaped name. That last one needs **both** halves — the identifier must read as a
+credential *and* the whole literal must be hex or base64 with no word structure. Name-proximity
+alone flags `secure::get_project_secret(&id, "aws-secret-access-key")`, which is a keychain key
+name; the literal test is what excludes it. Measured against the tree: 0 false positives, and it
+catches the real incident (`9b2f4fe`) when replayed.
+
+A line ending `pragma: allowlist secret` is skipped. Make a fixture obviously fake before reaching
+for it.
+
+**Why this exists:** `the_custom_env_fingerprint_never_carries_the_value` used the maintainer's
+real Gitea **site-admin** token as its fixture — a test about secrets not escaping, leaking one. It
+survived 92 commits and fourteen days in the public GitHub mirror, past five audit rounds and two
+independent reviews, because every one of them read the code under change and this sat in a test
+nobody had reason to open. Fixtures are never live values; there is no case where they need to be.
+
+## Settings export/import
+
+`commands::settings_export_commands`, `storage::settings_crypto`, `models::settings_export`
+(triple-c#35). Exports the *host* environment — global `AppSettings` plus the global secrets that
+live in the OS keychain instead: the shared Claude Code OAuth login and the model gateway's two
+keys. Per-project settings, per-project secrets, and anything in a project's Docker volumes are
+deliberately out of scope — this is not a project backup.
+
+- **`AppSettings` is not entirely the non-secret shape it looks like, and a review of this feature
+  caught the one place that isn't.** `WebTerminalSettings::access_token` is a live bearer
+  credential for a server that binds every interface — exporting `AppSettings` wholesale would
+  have carried it along as if it were as inert as a port number, and importing it would have
+  applied `web_terminal.enabled` and the token together with no more warning than any other
+  setting, letting a crafted export silently stand up a LAN-listening terminal on the next launch.
+  `export_settings`/`apply_settings_import` carve this one field out into `ExportedSecrets`
+  instead, with the same "only overwrite what the import actually has" treatment as the other
+  three secrets — except "leave it alone" has to be done by hand in `apply_settings_import`, since
+  unlike the keychain secrets this one lives inside the `AppSettings` blob that gets replaced
+  wholesale. `SettingsImportPreview::enables_web_terminal` also exists because of this: `enabled`
+  and the token are independent fields, and "this turns on a listening service" must not hide
+  inside a generic "settings replaced" summary. Read this as the standing example of the class of
+  thing to keep checking for in this feature, not a one-off fixed bug — any other field that looks
+  like config but is actually a live credential would have the same problem.
+- **Encrypted because it can carry live credentials, not for appearance's sake.** Argon2id derives
+  a 256-bit key from the user's password (memory-hard — meaningfully resistant to GPU/ASIC
+  brute-forcing, unlike PBKDF2 at any reasonable iteration count), AES-256-GCM does the actual
+  encryption. A wrong password fails GCM's authentication tag rather than producing silent
+  garbage. The salt and nonce are not secret and are written in the clear in the file's own
+  header — the salt's job is only to make two exports of the same password derive different keys,
+  and the nonce's only requirement is per-encryption uniqueness, which a fresh random draw on
+  every export already gives it.
+- **The save/open dialogs are opened from Rust**, the same boundary `file_commands.rs`'s
+  `pick_save_path`/`pick_files_to_upload` draw and document at length: a frontend-driven dialog
+  handing Rust a host path string is the exact shape of bug that produced this app's past
+  criticals. `preview_settings_import` resolves the chosen path itself and remembers it
+  (`AppState::pending_settings_import`) so `apply_settings_import` re-reads the same file without
+  a path ever crossing back over IPC. It also pins a hash of the file's ciphertext next to that
+  path, and `apply_settings_import` refuses to proceed if the file on disk no longer matches it —
+  otherwise confirming a preview would not actually be binding on what gets applied, which matters
+  given this feature's own threat model: a file shared between people may sit in a synced or
+  otherwise shared directory that changes between the two calls.
+- **The decrypted payload is not cached between preview and apply — only the password is reused.**
+  The frontend holds the password in React state and passes it to both calls; nothing in Rust
+  holds decrypted plaintext — secrets included — in memory for longer than one command's
+  execution, so `apply_settings_import` always re-decrypts rather than reusing anything
+  `preview_settings_import` computed. `preview_settings_import` returns counts and presence flags
+  only (`SettingsImportPreview`), never a secret value, so it's safe to hand to the frontend and
+  render directly.
+- **Import replaces settings wholesale, but only writes secrets actually present in the file.**
+  An import is "restore this environment," so the settings half is a full replace, not a
+  field-by-field merge. Secrets are different on purpose: an absent secret in the export means
+  "the source machine never had this configured," not "delete this on import" — a user who wants
+  to clear a secret already has dedicated UI for that (signing out of shared auth, clearing the
+  gateway key). Secrets are restored *before* the settings replace runs, not after — replacing
+  settings is what triggers `reconcile_gateway`, and restoring the other way round leaves a real
+  window where a gateway recreation happens against the destination's old keys.
+- **A restored gateway secret nudges a running gateway container to recreate itself, even when
+  nothing about the gateway's *shape* changed.** `reconcile_gateway`'s `gateway_shape_changed` only
+  compares port/provider/base URL/models — deliberately, since that's what's rendered into the
+  container's config — so a secret-only change (same shape, new key) is invisible to it. Left
+  alone, a running container would keep serving the old key material indefinitely after an import
+  that restored a new one. `apply_settings_import` tracks whether either gateway secret was
+  actually written and, if the gateway is enabled and its container both exists and is running,
+  calls `docker::gateway::ensure_gateway_running` directly afterward — its own fingerprint already
+  includes the secret rotation id (`storage::secure::get_gateway_secret_version`), so it recreates
+  exactly when it should and no more.
+- **A keychain write failing during import is reported back, not only logged.** Each of the three
+  `secure::store_*` calls collects its error into `SettingsImportOutcome::secret_restore_warnings`
+  in addition to logging it — an import that silently restores two of three secrets but not the
+  third must not read as unqualified success just because the settings half of the import (which
+  runs after, and is validated before any of this) went through. `apply_settings_import` returns
+  `SettingsImportOutcome { settings, secret_restore_warnings }` rather than bare `AppSettings` for
+  this reason; `ImportSettingsModal` shows any warnings alongside the "Settings imported" message.
+- **The imported settings are validated *before* any secret is written, not just before the
+  settings replace.** `apply_settings_import` calls
+  `settings_commands::validate_settings_update(&current, &settings)` — the same checks
+  `update_settings` runs internally, pulled out into its own function specifically so this caller
+  can run them first — and only proceeds to the three keychain writes if that passes. A review
+  caught the earlier ordering: writing secrets first meant a rejected import (a bad env var name, a
+  disallowed host path) still left the keychain overwritten with the file's secrets while the
+  settings themselves stayed unchanged, a silently half-applied state the error message gave no
+  hint of.
+- **`read_and_decrypt` checks `format_version` before attempting to parse the full payload, not
+  after.** A version bump that isn't deserialize-compatible is exactly the case that check exists
+  for, and parsing the full struct first would fail on the shape mismatch before the version check
+  ever ran. Neither error path interpolates what `serde_json` actually says into the message
+  shown to the user — its type-mismatch errors quote the offending value inline, and the plaintext
+  here can hold a live credential.
+- **The 8-character password minimum is enforced in `export_settings` itself, not only in the
+  export modal.** The frontend minimum is a UX nudge; the Rust command is the actual boundary a
+  weak password has to cross, and Argon2id's memory-hardness buys little against an attacker who
+  can just try a short password directly. Measured with `.chars().count()` (Unicode scalar values)
+  rather than `.len()` (bytes), to stay as close as this pair of languages allows to the frontend's
+  `.length` check (UTF-16 code units) — the two only diverge on astral-plane characters. The
+  derived key and both plaintext buffers — the payload built for export, and whatever `decrypt`
+  recovers on import — are wrapped in `zeroize::Zeroizing` for the same reason every other secret
+  in this codebase gets handled carefully — cheap insurance (`zeroize` is already pulled in
+  transitively via `aes-gcm`) for material that exists only to hold or produce live credentials.
+- **The preview also discloses non-blank custom base URLs** (`global_ollama`, `global_llamacpp`,
+  `global_openai_compatible`, `gateway.api_base`) so an import that would redirect model traffic to
+  a different server is visible in the confirmation dialog rather than discovered later — these are
+  endpoints, not secrets, so `SettingsImportPreview` carries and `describeImport` renders the actual
+  URL rather than just a presence flag. `describeImportWarnings` additionally calls out a web
+  terminal token that arrives with the terminal left *off*: `start_web_terminal` only mints a fresh
+  token when none is already set, so a planted token would otherwise activate silently the next
+  time someone turns the terminal on, with no import-time signal that it wasn't freshly generated.
+- **The preview also discloses a custom Docker image, and warns on one every time — not just on
+  change.** `custom_image_name`/`image_source` weren't in scope for the base-URL disclosure above,
+  but a review pointed out they're a sharper version of the same problem: this is the image *every*
+  project container is created from (`models::container_config::resolve_image_name`), so a crafted
+  export pointing it at an attacker-controlled image is a path to running arbitrary code with
+  whatever a project's containers are allowed to reach, not merely a redirected API endpoint.
+  `describeImportWarnings` fires on `image_source == Custom` unconditionally rather than only when
+  it differs from the destination's current value, since re-importing the same risky configuration
+  is still worth surfacing every time a user confirms an import.
+- **Every free-form string a preview surfaces is sanitized and length-capped before it's built.**
+  `SettingsImportPreview::from_payload`'s `sanitize_for_preview` strips control characters and caps
+  at 100 characters (`MAX_PREVIEW_STRING_LEN`) for every base URL and the custom image name — a
+  review noted that, unlike the count- and boolean-derived fields the preview started with, these
+  are verbatim strings from a not-yet-trusted decrypted payload rendered directly into the
+  confirmation dialog. Unbounded, a single pathological value (very long, or holding embedded
+  newlines) could push the security warnings above the scroll fold in the dialog that exists
+  specifically to make them unmissable — the frontend's `<li>`/warning boxes also get `break-all`
+  as a second layer against the same failure mode.
+
+## Packaging
+
+Linux ships as `.deb`, `.rpm` and AppImage, all three built by `build-app.yml` (releases) and
+`build-app-preview.yml` (the PR check). **There is deliberately no Arch package.** A
+`triple-c-bin` `PKGBUILD` and a `publish-arch-package.yml` existed and were removed; they live on
+`hold/arch-packaging`. Do not re-add them without the piece that was always missing: the package
+was never on the AUR, so it was a manual `pacman -U` of a downloaded file — the same gesture as
+the AppImage, for a second artifact to keep working. Being `workflow_dispatch`-only it also
+reached 1 release in 28, while `HOW-TO-USE.md` told Arch users to download it from every release.
+An AUR account and its SSH key as a repo secret are what would make it worth having; until then
+the AppImage is the Arch story.
+
+`scripts/install-appimage.sh` is the desktop-integration half, and it exists because an AppImage
+has no installer: it extracts the bundled icons into `~/.local/share/icons/hicolor` and writes a
+`.desktop` entry. It **rewrites** the `Exec` line rather than copying the bundled entry — the
+bundled one is `Exec=triple-c`, which resolves only inside the AppImage's own mount, so a
+verbatim copy yields a launcher entry that starts nothing. It keeps `StartupWMClass` exactly as
+the bundle sets it, which is what lets the shell match the window to the entry. Extraction uses
+`--appimage-extract`, which needs no FUSE, so the script works before `fuse2` is installed.
+
 ## Testing
 
 Frontend tests use Vitest with jsdom environment and React Testing Library. Setup file at `src/test/setup.ts`. Run a single test file:

HOW-TO-USE.md

@@ -6,6 +6,7 @@ Triple-C (Claude-Code-Container) is a desktop application that runs Claude Code
 
 ## Table of Contents
 
+- [Installation](#installation)
 - [Prerequisites](#prerequisites)
 - [First Launch](#first-launch)
 - [The Interface](#the-interface)
@@ -32,6 +33,63 @@ Triple-C (Claude-Code-Container) is a desktop application that runs Claude Code
 
 ---
 
+## Installation
+
+Download the build for your platform from [GitHub Releases](https://github.com/shadowdao/triple-c/releases/latest).
+
+| Platform | File | Install |
+|----------|------|---------|
+| **Windows** | `Triple-C_<version>_x64-setup.exe` or `.msi` | Run the installer. |
+| **macOS** | `Triple-C_<version>_universal.dmg` | Open the `.dmg` and drag Triple-C to Applications. |
+| **Debian / Ubuntu** | `Triple-C_<version>_amd64.deb` | `sudo apt install ./Triple-C_<version>_amd64.deb` |
+| **Fedora / RHEL** | `Triple-C-<version>-1.x86_64.rpm` | `sudo dnf install ./Triple-C-<version>-1.x86_64.rpm` |
+| **Arch / CachyOS / other Linux** | `Triple-C_<version>_amd64.AppImage` | `chmod +x` it, then run it directly. See the AppImage notes below. |
+
+> **macOS note:** The app is not signed or notarized. On first launch, macOS Gatekeeper may block it — right-click the app and select "Open" to bypass, or remove the quarantine attribute: `xattr -cr /Applications/Triple-C.app`.
+
+> **AppImage note:** Two things are worth knowing. Running an AppImage needs FUSE 2, which Arch and CachyOS do not install by default — `sudo pacman -S fuse2` once, or run it with `--appimage-extract-and-run` to sidestep FUSE entirely. And an AppImage is just an executable file: nothing registers it with the desktop, so it will not appear in your app launcher on its own. Run [`scripts/install-appimage.sh`](scripts/install-appimage.sh) to add a launcher entry and icons — see [Adding an AppImage to the app launcher](#adding-an-appimage-to-the-app-launcher).
+
+> **No Arch package.** There was a `triple-c-bin` `.pkg.tar.zst` attached to some releases, built by a maintainer-triggered workflow. It was never on the AUR, so installing it meant downloading a file and running `pacman -U` — no better than the AppImage — and being manual-only it reached 1 release in 28, which made the promise of it worse than not making it. The `PKGBUILD` and its workflow are preserved on the `hold/arch-packaging` branch if an AUR package is ever worth doing properly.
+
+### Adding an AppImage to the app launcher
+
+An AppImage is a single executable file and nothing else. It carries a `.desktop`
+entry and icons *inside* itself, but nothing on your system ever reads them,
+because nothing installed it — so it will not show up in your app launcher, and
+running it from a file manager gives you a generic icon in the taskbar.
+
+Put the AppImage somewhere stable first — `~/Apps` or `~/.local/bin`, not
+`~/Downloads` — because the launcher entry points at wherever the file is:
+
+```bash
+mkdir -p ~/Apps
+mv ~/Downloads/Triple-C_*_amd64.AppImage ~/Apps/
+./scripts/install-appimage.sh ~/Apps/Triple-C_0.4.17_amd64.AppImage
+```
+
+That copies the bundled icons into `~/.local/share/icons/hicolor` and writes
+`~/.local/share/applications/triple-c.desktop` pointing at the file you named.
+No sudo, nothing outside your home directory, and the AppImage itself is never
+copied or moved. To remove the entry again:
+
+```bash
+./scripts/install-appimage.sh --uninstall
+```
+
+The script rewrites the `Exec` line rather than reusing the bundled `.desktop`
+verbatim: the bundled one says `Exec=triple-c`, which resolves only inside the
+running AppImage's own mount, so a launcher entry copied straight out of the
+bundle would appear in the menu and then fail to start anything.
+
+Two follow-ups worth knowing:
+
+- **Upgrading.** The entry names one specific file. If you replace the AppImage
+  with a newer version under a different filename, re-run the script against the
+  new one. Keeping a stable name (`~/Apps/Triple-C.AppImage`) avoids this.
+- **The icon may not appear until you log out.** That is the desktop shell's
+  icon cache, not a failed install — see
+  [App Icon Missing After Installing (Linux)](#app-icon-missing-after-installing-linux).
+
 ## Prerequisites
 
 ### Docker
@@ -228,7 +286,7 @@ buttons. Below that are six tabs:
 | **Sessions** | Past Claude Code conversations stored on this project's config volume, each with a **Resume** button |
 | **Automation** | The scheduled tasks running inside this container — see [Automation & Scheduled Tasks](#automation--scheduled-tasks) |
 | **Config** | All per-project configuration — see [Project Configuration](#project-configuration) |
-| **Files** | Browse, view and rename files inside the container — see [Files](#files) for how files get in and out |
+| **Files** | Browse, view and rename files inside the container, and move files between it and your own machine — see [Files](#files) |
 | **Browser** | Watch — and take over — the browser Claude is driving with Playwright, see [The Browser Tab](#the-browser-tab) |
 
 ### Sessions
@@ -351,7 +409,7 @@ it. The sidebar row carries only the two hover controls.
 | **Force stop** | Project Home header | Starting / Stopping | Interrupts a transition that is stuck |
 | **Open Claude Terminal** | Project Home header; sidebar hover control; `Ctrl+T` | Running | Opens a new Claude Code terminal tab |
 | **Shell** | Project Home header | Running | Opens a bash login shell tab in the container (no Claude Code) |
-| **Files** | Project Home header, and the **Files** tab | Running | Switches to the Files tab to browse, view and rename files inside the container |
+| **Files** | Project Home header, and the **Files** tab | Running | Switches to the Files tab to browse, view and rename files inside the container, upload files into it and save one back out |
 | **Config** | The **Config** tab | Always | Per-project configuration (most fields need the container stopped) |
 | **Back up container** | **⋯** overflow menu | A container exists | Saves a `.tar.gz` archive of the container to a location you choose |
 | **Reset container…** | **⋯** overflow menu | Stopped or Error | Destroys the container, snapshot image and both volumes, then recreates from the base image (wipes `~/.claude`) — asks first |
@@ -1170,8 +1228,8 @@ When you scroll up in the terminal to review previous output, a **Jump to Curren
 
 ### Files
 
-The **Files** tab of Project Home browses inside a running container. It works entirely on the
-container side — it never reads or writes anything on your own machine. You can:
+The **Files** tab of Project Home browses inside a running container, and moves files between it
+and your own machine. You can:
 
 - **Browse** the container filesystem, starting at `/workspace`, with breadcrumb navigation.
   Double-click a folder to open it, or the `..` row to go up; the arrow keys, Home and End move
@@ -1181,32 +1239,50 @@ container side — it never reads or writes anything on your own machine. You ca
 - **Rename** an entry, from the row's Rename button or by pressing `F2`. A rename never moves a
   file between folders
 - **New folder** in the directory on screen
+- **Upload…**, from the toolbar, to copy files from your machine into the directory on screen
+- **Save to host…**, from a file's own row, to write that one file out to your machine
 - **Refresh** the directory listing at any time
 
 The listing shows file names, sizes, and modification dates, and marks symbolic links.
 
 #### Getting files in and out
 
-The Files tab deliberately does **not** copy files between your computer and the container. There
-are two supported routes, and they are the ones to use:
+**Upload…** opens a file dialog on your machine, and whatever you choose is copied into the
+directory currently on screen. Uploaded files arrive owned by you inside the container, not by
+root. You can pick several files in one dialog; each is handled on its own, so if a folder or an
+over-sized file is among them, it is named in the message and the rest still arrive. Uploads are
+capped at **256 MB per file** — for anything larger, mount the folder into the project instead and
+skip the copying altogether.
 
-- **To get a file in:** drag it from your desktop and **drop it onto the Terminal tab**. The file
-  is copied into the container and its path is typed into the terminal for you, ready to hand to
-  Claude Code. (You can also drop it onto the terminal's *Following* toggle — the whole pane is a
-  drop target.)
-- **To get files out:** use **Back up container** in Project Home's **⋯** overflow menu. It writes
-  a `.tar.gz` of the workspace and the container's `~/.claude` config to a location you choose.
-  For a single file, `cat` it in a terminal, or work in a project folder that is mounted from your
-  host in the first place — those files are already on both sides.
+**Save to host…** does the reverse, for one file: a save dialog opens, you choose where the file
+goes, and it is written there. The button sits on the file's own row, and only on files. For a
+whole directory, use **Back up container** in Project Home's **⋯** overflow menu, which writes a
+`.tar.gz` of the workspace and the container's `~/.claude` config to a location you choose — that
+is still the right tool for a tree.
 
-Both routes refuse a destination whose path passes through a hidden folder — anything with a
-component beginning with `.`, such as `~/.ssh`, `~/.local/bin` or `~/.config`. That rule catches
-more than it strictly needs to (a path that happens to resolve through `~/.cache` or
-`node_modules/.pnpm` is refused as well), and the refusal says which folder tripped it. Choose a
-visible location such as `~/Documents` or `~/Downloads`.
+Dragging a file from your desktop and **dropping it onto the Terminal tab** works too, and is often
+the quickest way in when you are already typing: the file is copied into the container and its path
+is typed into the terminal for you, ready to hand to Claude Code. (The whole terminal pane is a
+drop target, including its *Following* toggle.) The Files pane itself is not a drop target.
+
+Both dialogs are opened by Triple-C itself rather than by the page you are looking at. The page
+cannot name a place on your machine — it can only ask for a dialog — and nothing is read or written
+until you pick somewhere in it. Closing a dialog without choosing is not an error: nothing happens,
+and nothing is said about it.
+
+Every one of these routes refuses a location whose path passes through a hidden *folder* — anything
+with a component beginning with `.`, such as `~/.ssh`, `~/.cache` or `~/.local/share` — or a system
+location, and it checks both the path as written and where it points after any symbolic links. That
+rule catches more than it strictly needs to, so now and then it will refuse a place you genuinely
+meant, `~/.config` among them. The refusal is a plain sentence saying so; choose a visible location
+such as `~/Documents` or `~/Downloads`.
+
+The *file's own name* is a different matter, and dotfiles are fine: `.env`, `.gitignore` and the
+rest save normally, since you chose the name in the save dialog yourself. Only the folders on the
+way are judged.
 
 If you already keep the project in a folder mounted into the container, the simplest answer is
-usually neither of the above: edit the file on your host and it is already inside.
+usually none of the above: edit the file on your host and it is already inside.
 
 ### Terminal Rendering
 
@@ -1518,3 +1594,9 @@ cp ~/.claude.json ~/.claude.json.bak && jq 'with_entries(select(.key | startswit
 ```
 
 This backs up your config and removes the corrupted marketplace entries. Claude Code will re-download them cleanly on the next startup.
+
+### App Icon Missing After Installing (Linux)
+
+If Triple-C's icon shows as generic or blank right after installing — in the app menu, taskbar, and window titlebar alike — **log out and back in.**
+
+Desktop shells (GNOME Shell, KDE Plasma) cache the list of installed apps and their resolved icons in memory when the shell starts, for performance. A freshly installed package's icon files land on disk correctly and its install hooks do rebuild the on-disk icon cache, but an already-running shell doesn't always notice — on X11 there used to be a way to soft-restart just the shell (GNOME's Alt+F2 → `r`) to force a reload, but under Wayland the shell *is* the compositor, so restarting it means ending the session. Logging out and back in starts a fresh shell that reads the current on-disk state, which picks the icon up.

README.md

@@ -24,7 +24,7 @@ This file is the architectural tour: what each subsystem is and why it works the
 - [Permission Modes](#permission-modes)
 - [Containers](#containers) — lifecycle, base-image migration, mounts, CA certificates, sibling containers
 - [Models and Authentication](#models-and-authentication) — backends, model aliases, gateway, shared token
-- [Bridges to the Host](#bridges-to-the-host) — URL relay, auth bridge, browser view
+- [Bridges to the Host](#bridges-to-the-host) — URL relay, auth bridge, browser view, host file transfers
 - [Inside a Project](#inside-a-project) — capability tiles, Mission Control, web terminal, speech-to-text
 - [Key Files](#key-files) · [CSS / Styling Notes](#css--styling-notes) · [Container Image](#container-image)
 
@@ -105,7 +105,7 @@ configuration. Per-project configuration lives in the Config tab rather than in
 | **Sessions** | Past Claude Code conversations read from the config volume, with **Resume** |
 | **Automation** | The container's `triple-c-scheduler` tasks — create, edit, enable/disable, run now, read logs, remove, and completion notifications |
 | **Config** | Workspace (name, folders), Model (backend), Access (SSH, git, env vars, port mappings), Runtime (permission mode, sandbox, Docker access, Mission Control, instructions, Claude Code settings) |
-| **Files** | Browse, view and rename files inside the container. Container-side only: to get a file *in*, drop it on the Terminal tab; to get files *out*, use **Back up container** |
+| **Files** | Browse, view, rename and create folders inside the container, upload host files into the directory on screen, and save one file back out to the host — see [Host File Transfers](#host-file-transfers). A whole tree still comes out through **Back up container** |
 | **Browser** | Watch and take over the Playwright browser inside the container — see [Browser View](#browser-view) |
 
 Container start/stop progress is reported inline (on the sidebar row and in the Project Home
@@ -442,6 +442,39 @@ per project.
   binds, but never `@playwright/cli`, which is the viewer. It is what binds sessions automatically
   once Playwright is present — not a setup route.
 
+### Host File Transfers
+
+Four routes move files across the boundary: **Upload…** and the per-row **Save to host…** in the
+Files tab, a file dropped onto the Terminal tab, and **Back up container**. All four share one path
+policy in `commands/file_commands.rs`.
+
+- **The OS dialogs are opened by Rust, not by the webview.** `upload_files_to_container` and
+  `download_container_file` drive `tauri-plugin-dialog` themselves and take nothing but a project
+  id and a container-side path; `FilesTab.tsx` imports no dialog plugin and `useFileManager`'s
+  `uploadFiles` takes no argument at all. The web UI can ask for a dialog, and that is the whole of
+  its influence over where a file comes from or goes — it cannot name a host path as an *input*.
+  This is a boundary rather than a convention: a dialog the page itself opens is only as trustworthy
+  as the page. Be precise about the limit, though — host paths still travel *outward* in error text,
+  canonical ones included, so this closes the inbound direction and not both.
+- **The dialog's pre-filled name is sanitized, because a container authored it.** On Windows the
+  save dialog parses its name box as a path, and a container can name a file
+  `..\..\Users\you\…\Word\STARTUP\x.dotm` — one POSIX segment, so nothing upstream objects.
+  `suggested_save_name` replaces every separator and every character NTFS refuses, so the string
+  cannot be a path on any platform this ships to.
+- **One policy for every host path.** A source or destination whose path passes through a hidden
+  folder (`~/.ssh`, `~/.cache`, `~/.local/share`, anything dot-prefixed) or a system location is
+  refused, and the check is applied both to the path as written and to what it resolves to after
+  symlinks. It over-catches deliberately, so it will occasionally refuse somewhere a person
+  genuinely meant — `~/.config`, say — and the refusal is a sentence naming the folder that tripped
+  it, not an errno.
+- **Uploads are capped at 256 MB per file**; past that the answer is a mount, not a copy. One
+  dialog's selection is handled file by file, so a folder or an oversized file among the selection
+  is reported by name and does not stop the others. Uploaded files land owned by the container user,
+  not root. A cancelled dialog is silent — `Ok(None)`, not an error.
+- **`download_container_file` is one file and files only** — no button on a folder row. A directory
+  is what `download_container_backup` is for. There is no drop target on the Files pane; the
+  Terminal tab keeps the one it has.
+
 ## Inside a Project
 
 ### Container Introspection (Capability Tiles)
@@ -513,7 +546,7 @@ Triple-C includes optional speech-to-text powered by [Faster Whisper](https://gi
 | `app/src/components/projects/home/AutomationTab.tsx` | Scheduler tasks: create, toggle, run now, logs, remove, notifications |
 | `app/src/components/projects/home/TaskEditorModal.tsx` | Create/edit a scheduled task; `taskValidation.ts` holds the cron and schedule rules |
 | `app/src/components/projects/home/ConfigTab.tsx` | Config sections (Workspace, Model, Access, Runtime) |
-| `app/src/components/projects/home/FilesTab.tsx` | Container-side file browser (navigate, view, rename, new folder) |
+| `app/src/components/projects/home/FilesTab.tsx` | Container-side file browser (navigate, view, rename, new folder) plus **Upload…** and per-row **Save to host…**; imports no dialog plugin — the dialogs are Rust's |
 | `app/src/components/projects/home/BrowserTab.tsx` | Browser view pane: detect, install, watch, take over, pop out |
 | `app/src/components/projects/home/OpenPageDialog.tsx` | Open a URL in the container's browser at a chosen viewport |
 | `app/src/components/projects/home/ContainerMigrationBanner.tsx` | Base-image staleness banner, migration progress, resume/rollback |
@@ -536,7 +569,7 @@ Triple-C includes optional speech-to-text powered by [Faster Whisper](https://gi
 | `app/src/hooks/useTerminal.ts` | Terminal session management (claude and bash modes) |
 | `app/src/hooks/useProjectActions.ts` | Start/stop/reset/backup and terminal-opening helpers |
 | `app/src/hooks/useContainerMigration.ts` | Staleness polling, migration run, resume and rollback |
-| `app/src/hooks/useFileManager.ts` | File browser operations (list, navigate, rename, mkdir) |
+| `app/src/hooks/useFileManager.ts` | File browser operations (list, navigate, rename, mkdir) and the host transfers (upload, save one file out); never handles a host path |
 | `app/src/hooks/useClaudeAuth.ts` | Shared-token status and acquisition |
 | `app/src/hooks/useSTT.ts` | Speech-to-text recording, transcription, and container management |
 | `app/src/lib/urlRelay.ts` | Host-side relay validation: OSC 7777 parsing, http/https allowlist, rate limiting |
@@ -561,7 +594,7 @@ Triple-C includes optional speech-to-text powered by [Faster Whisper](https://gi
 | `app/src-tauri/src/commands/inspect_commands.rs` | Read-only container views: sessions, capabilities, scheduler tasks |
 | `app/src-tauri/src/commands/auth_token_commands.rs` | `claude setup-token` flow, redaction, keychain storage |
 | `app/src-tauri/src/commands/auth_bridge_commands.rs` | Auth bridge enable/status commands |
-| `app/src-tauri/src/commands/file_commands.rs` | Container-side file commands (list, read, rename, mkdir) plus `download_container_backup` |
+| `app/src-tauri/src/commands/file_commands.rs` | Container-side file commands (list, read, rename, mkdir), the host transfers `upload_files_to_container` and `download_container_file` — each opening its own OS dialog here in Rust — plus `download_container_backup`, and the hidden-folder path policy all of them share |
 | `app/src-tauri/src/commands/stt_commands.rs` | STT start/stop/transcribe Tauri commands |
 | `app/src-tauri/src/commands/web_terminal_commands.rs` | Web terminal start/stop/status Tauri commands |
 | `app/src-tauri/src/models/project.rs` | Project struct (backend, `PermissionMode`, Docker access, Claude Code settings, Mission Control, auth bridge, browser view, CA path, shared-token opt-out) |

TECHNICAL.md

@@ -412,13 +412,12 @@ triple-c/
 │
 ├── .gitea/
 │   └── workflows/
-│       ├── build-app.yml          # Build Tauri app (Linux/macOS/Windows)
+│       ├── build-app.yml            # Build Tauri app (Linux/macOS/Windows); mirrors releases to GitHub inline
 │       ├── build-app-preview.yml    # Preview builds
 │       ├── build.yml                # Build container image (multi-arch)
 │       ├── build-stt.yml            # Build the STT image
-│       ├── sync-release.yml       # Mirror releases to GitHub
 │       ├── backfill-releases.yml    # Bulk copy releases to GitHub
-│       └── cleanup-releases.yml   # Prune old releases
+│       ├── cleanup-releases.yml     # Prune old releases
 │
 └── app/                           # Tauri v2 desktop application
     ├── package.json               # React, xterm.js, zustand, tailwindcss
@@ -436,7 +435,7 @@ triple-c/
     │   │   ├── useClaudeAuth.ts   # Shared token status + acquisition
     │   │   ├── useContainerProgress.ts # container-progress events → inline progress
     │   │   ├── useDocker.ts       # Docker status, image build/pull
-    │   │   ├── useFileManager.ts  # File browser operations
+    │   │   ├── useFileManager.ts  # File browser operations + host transfers
     │   │   ├── useInstallHelper.ts # Guided Docker installation
     │   │   ├── useKeyboardShortcuts.ts # Ctrl+T / Ctrl+Shift+W / Ctrl+Tab / Ctrl+1..9
     │   │   ├── useProjectActions.ts # Start/stop/reset/backup, open terminals
@@ -464,7 +463,7 @@ triple-c/
     │       │   │   ├── SessionsTab.tsx   # Past Claude sessions + Resume
     │       │   │   ├── AutomationTab.tsx # Scheduler tasks + notifications
     │       │   │   ├── ConfigTab.tsx     # Config section host
-    │       │   │   ├── FilesTab.tsx      # In-container file browser
+    │       │   │   ├── FilesTab.tsx      # In-container file browser, upload / save to host
     │       │   │   ├── CapabilityTiles.tsx # Read-only capability counts
     │       │   │   ├── format.ts         # Age / size / uptime formatting
     │       │   │   └── config/           # WorkspaceSection, ModelSection,
@@ -504,7 +503,7 @@ triple-c/
             │   ├── auth_token_commands.rs   # claude setup-token flow, redaction, keychain
             │   ├── aws_commands.rs          # AWS profile/region discovery
             │   ├── docker_commands.rs       # Docker status, image ops
-            │   ├── file_commands.rs         # File browser (browse, view, rename)
+            │   ├── file_commands.rs         # File browser + host transfers (Rust-opened dialogs)
             │   ├── help_commands.rs         # Serves HOW-TO-USE.md to the Help dialog
             │   ├── inspect_commands.rs      # Sessions, capabilities, scheduler tasks
             │   ├── install_helper_commands.rs # Guided Docker installation

app/package.json

@@ -9,7 +9,8 @@
     "preview": "vite preview",
     "tauri": "tauri",
     "test": "vitest run",
-    "test:watch": "vitest"
+    "test:watch": "vitest",
+    "hooks": "git -C .. config core.hooksPath .githooks && echo \"pre-commit secret scan enabled\""
   },
   "dependencies": {
     "@tauri-apps/api": "^2",

app/src-tauri/Cargo.lock

@@ -8,6 +8,41 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
+[[package]]
+name = "aead"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d122413f284cf2d62fb1b7db97e02edb8cda96d769b16e443a4f6195e35662b0"
+dependencies = [
+ "crypto-common",
+ "generic-array",
+]
+
+[[package]]
+name = "aes"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b169f7a6d4742236a0a00c541b845991d0ac43e546831af1249753ab4c3aa3a0"
+dependencies = [
+ "cfg-if",
+ "cipher",
+ "cpufeatures",
+]
+
+[[package]]
+name = "aes-gcm"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "831010a0f742e1209b3bcea8fab6a8e149051ba6099432c8cb2cc117dec3ead1"
+dependencies = [
+ "aead",
+ "aes",
+ "cipher",
+ "ctr",
+ "ghash",
+ "subtle",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.4"
@@ -47,6 +82,18 @@ version = "1.0.102"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
 
+[[package]]
+name = "argon2"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3c3610892ee6e0cbce8ae2700349fcf8f98adb0dbfbee85aec3c9179d29cc072"
+dependencies = [
+ "base64ct",
+ "blake2",
+ "cpufeatures",
+ "password-hash",
+]
+
 [[package]]
 name = "async-broadcast"
 version = "0.7.2"
@@ -280,6 +327,12 @@ version = "0.22.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
+[[package]]
+name = "base64ct"
+version = "1.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2af50177e190e07a26ab74f8b1efbfe2ef87da2116221318cb1c2e82baf7de06"
+
 [[package]]
 name = "bit-set"
 version = "0.8.0"
@@ -310,6 +363,15 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "blake2"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "46502ad458c9a52b69d4d4d32775c788b7a1b85e8bc9d482d92250fc0e3f8efe"
+dependencies = [
+ "digest",
+]
+
 [[package]]
 name = "block-buffer"
 version = "0.10.4"
@@ -569,6 +631,16 @@ dependencies = [
  "windows-link 0.2.1",
 ]
 
+[[package]]
+name = "cipher"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "773f3b9af64447d2ce9850330c473515014aa235e6a783b02db81ff39e4a3dad"
+dependencies = [
+ "crypto-common",
+ "inout",
+]
+
 [[package]]
 name = "combine"
 version = "4.6.7"
@@ -694,6 +766,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78c8292055d1c1df0cce5d180393dc8cce0abec0a7102adb6c7b1eef6016d60a"
 dependencies = [
  "generic-array",
+ "rand_core 0.6.4",
  "typenum",
 ]
 
@@ -753,6 +826,15 @@ version = "0.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "52560adf09603e58c9a7ee1fe1dcb95a16927b17c127f0ac02d6e768a0e25bc1"
 
+[[package]]
+name = "ctr"
+version = "0.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0369ee1ad671834580515889b80f2ea915f23b8be8d0daa4bbaf2ac5c7590835"
+dependencies = [
+ "cipher",
+]
+
 [[package]]
 name = "darling"
 version = "0.20.11"
@@ -923,6 +1005,7 @@ checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
 dependencies = [
  "block-buffer",
  "crypto-common",
+ "subtle",
 ]
 
 [[package]]
@@ -1550,6 +1633,16 @@ dependencies = [
  "syn 2.0.117",
 ]
 
+[[package]]
+name = "ghash"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0d8a4362ccb29cb0b265253fb0a2728f592895ee6854fd9bc13f2ffda266ff1"
+dependencies = [
+ "opaque-debug",
+ "polyval",
+]
+
 [[package]]
 name = "gio"
 version = "0.18.4"
@@ -2114,6 +2207,15 @@ dependencies = [
  "cfb",
 ]
 
+[[package]]
+name = "inout"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "879f10e63c20629ecabbb64a8010319738c66a5cd0c29b02d63d272b03751d01"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "ipnet"
 version = "2.11.0"
@@ -2831,6 +2933,12 @@ version = "1.21.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
 
+[[package]]
+name = "opaque-debug"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08d65885ee38876c4f86fa503fb49d7b507c2b62552df7c70b2fce627e06381"
+
 [[package]]
 name = "open"
 version = "5.3.3"
@@ -2913,6 +3021,17 @@ dependencies = [
  "windows-link 0.2.1",
 ]
 
+[[package]]
+name = "password-hash"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "346f04948ba92c43e8469c1ee6736c7563d71012b17d40745260fe106aac2166"
+dependencies = [
+ "base64ct",
+ "rand_core 0.6.4",
+ "subtle",
+]
+
 [[package]]
 name = "pathdiff"
 version = "0.2.3"
@@ -3194,6 +3313,18 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "polyval"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d1fe60d06143b2430aa532c94cfe9e29783047f06c0d7fd359a9a51b729fa25"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "opaque-debug",
+ "universal-hash",
+]
+
 [[package]]
 name = "potential_utf"
 version = "0.1.4"
@@ -5149,6 +5280,8 @@ dependencies = [
 name = "triple-c"
 version = "0.4.0"
 dependencies = [
+ "aes-gcm",
+ "argon2",
  "axum",
  "base64 0.22.1",
  "bollard",
@@ -5174,6 +5307,7 @@ dependencies = [
  "tokio",
  "tower-http",
  "uuid",
+ "zeroize",
 ]
 
 [[package]]
@@ -5287,6 +5421,16 @@ version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"
 
+[[package]]
+name = "universal-hash"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc1de2c688dc15305988b563c3854064043356019f97a4b46276fe734c4f07ea"
+dependencies = [
+ "crypto-common",
+ "subtle",
+]
+
 [[package]]
 name = "untrusted"
 version = "0.9.0"

app/src-tauri/Cargo.toml

@@ -36,6 +36,9 @@ tower-http = { version = "0.6", features = ["cors"] }
 base64 = "0.22"
 rand = "0.9"
 local-ip-address = "0.6"
+argon2 = "0.5"
+aes-gcm = "0.10"
+zeroize = "1"
 
 [dev-dependencies]
 # `test-util` (not part of tokio's `full`) lets the auto-start retry tests run

app/src-tauri/src/commands/mod.rs

@@ -10,6 +10,7 @@ pub mod install_helper_commands;
 pub mod migration_commands;
 pub mod project_commands;
 pub mod settings_commands;
+pub mod settings_export_commands;
 pub mod stt_commands;
 pub mod terminal_commands;
 pub mod update_commands;

app/src-tauri/src/commands/project_commands.rs

@@ -2,7 +2,7 @@ use tauri::{Emitter, State};
 
 use crate::commands::aws_commands;
 use crate::docker;
-use crate::models::{container_config, AppSettings, Backend, BedrockAuthMethod, Project, ProjectPath, ProjectStatus};
+use crate::models::{container_config, AppSettings, Backend, BedrockAuthMethod, Project, ProjectPath, ProjectRemovalReport, ProjectResetOutcome, ProjectStatus};
 use crate::storage::secure;
 use crate::AppState;
 
@@ -696,7 +696,7 @@ pub async fn add_project(
 pub async fn remove_project(
     project_id: String,
     state: State<'_, AppState>,
-) -> Result<(), String> {
+) -> Result<ProjectRemovalReport, String> {
     // **H-2: the only writer of these three categories that held nothing.**
     // This purges migration artifacts, removes `triple-c-snapshot-{id}` and
     // both named volumes — and a compaction resolves that same tag when its
@@ -722,12 +722,76 @@ pub async fn remove_project(
     // holding an entire snapshot image that nothing will ever reference again.
     crate::commands::migration_commands::purge_migration_artifacts(&project_id).await;
 
-    // Stop and remove container if it exists
-    if let Some(ref project) = state.projects_store.get(&project_id) {
-        if let Some(ref container_id) = project.container_id {
+    // Stop and remove container if it exists. Everything named in `report`
+    // below is what will be unreachable the moment this function drops the
+    // project record — see [`ProjectRemovalReport`] and
+    // `storage::pending_cleanup`, which is what makes it reachable anyway.
+    let mut report = ProjectRemovalReport::default();
+    let existing_project = state.projects_store.get(&project_id);
+
+    if let Some(ref project) = existing_project {
+        // Resolved via `find_existing_container` unconditionally rather than
+        // trusting `project.container_id` — that field can be *stale*, not
+        // just absent: `start_project_container_locked`'s recreate path
+        // removes the old container, creates a new one, and does not persist
+        // the new id until after `start_container` succeeds, so a start
+        // failure in between (a missing `/dev/net/tun`, an image that exits
+        // immediately) leaves the stored id pointing at a container that no
+        // longer exists while a live one sits under the same deterministic
+        // name. Removing by a stale id then 404s — success as far as Docker
+        // is concerned — while the real container survives to block every
+        // subsequent volume removal with a 409, with nothing in the report
+        // ever naming it. `find_existing_container` is what every other
+        // destroyer of a project's container already resolves through
+        // (`start_project_container`, migration's recreate paths) for this
+        // exact reason.
+        //
+        // A `Docker unreachable` error here is treated as "assume a
+        // container is still there" rather than "assume none is", matching
+        // `remove_volumes_by_name`'s fail-closed handling of the same
+        // situation — the alternative silently drops the one resource most
+        // likely to block everything else if it does exist.
+        //
+        // Exec sessions are closed for `project.container_id` unconditionally,
+        // before the lookup above and regardless of whether it succeeds —
+        // that is host-side state with no Docker dependency, so it must not
+        // wait on a daemon that might not answer. Resolving through
+        // `find_existing_container` instead of using it directly would leave
+        // these open in exactly the two cases this whole change exists to
+        // handle: Docker unreachable (no id resolved, no way to ever close
+        // them again once the project record is gone) and the stale-id race
+        // (sessions were opened against the container that actually exists,
+        // which is what gets resolved below, not the stored id).
+        if let Some(ref stored_id) = project.container_id {
+            state.exec_manager.close_sessions_for_container(stored_id).await;
+        }
+        let container_ref = match docker::find_existing_container(project).await {
+            Ok(found) => found,
+            Err(e) => {
+                log::warn!(
+                    "Could not check for an existing container for project {}: {}",
+                    project_id, e
+                );
+                report.container = Some(project.container_name());
+                None
+            }
+        };
+        if let Some(ref container_id) = container_ref {
+            if project.container_id.as_deref() != Some(container_id.as_str()) {
                 state.exec_manager.close_sessions_for_container(container_id).await;
+            }
             let _ = docker::stop_container(container_id).await;
-            let _ = docker::remove_container(container_id).await;
+            if let Err(e) = docker::remove_container(container_id).await {
+                log::warn!(
+                    "Failed to remove container {} for project {}: {}",
+                    container_id, project_id, e
+                );
+                // Recorded by name, not id: the name is the stable handle a
+                // later retry can still resolve (Docker's remove-container
+                // call accepts either), and it is what `container_ref` above
+                // falls back to finding in the first place.
+                report.container = Some(project.container_name());
+            }
         }
 
         // Legacy MCP cleanup (pre-MCP-removal installs): drop any leftover MCP
@@ -738,10 +802,9 @@ pub async fn remove_project(
         // Clean up the snapshot image + volumes
         if let Err(e) = docker::remove_snapshot_image(project).await {
             log::warn!("Failed to remove snapshot image for project {}: {}", project_id, e);
+            report.image = Some(docker::get_snapshot_image_name(project));
         }
-        if let Err(e) = docker::remove_project_volumes(project).await {
-            log::warn!("Failed to remove project volumes for project {}: {}", project_id, e);
-        }
+        report.volumes = docker::remove_project_volumes(project).await;
     }
 
     // Clean up keychain secrets for this project
@@ -749,7 +812,216 @@ pub async fn remove_project(
         log::warn!("Failed to delete keychain secrets for project {}: {}", project_id, e);
     }
 
-    state.projects_store.remove(&project_id)
+    if !report.is_clean() {
+        let record = crate::storage::pending_cleanup::PendingCleanup {
+            project_id: project_id.clone(),
+            project_name: existing_project.map(|p| p.name).unwrap_or_default(),
+            container_id: report.container.clone(),
+            image: report.image.clone(),
+            volumes: report.volumes.clone(),
+            recorded_at: chrono::Utc::now().to_rfc3339(),
+        };
+        match crate::storage::pending_cleanup::save(&record) {
+            Ok(()) => {
+                report.retry_scheduled = true;
+                log::warn!(
+                    "Project {} removed; could not confirm these Docker resources were removed: \
+                     {:?} — recorded for automatic retry on next launch",
+                    project_id, report
+                );
+            }
+            Err(e) => {
+                report.retry_scheduled = false;
+                log::error!(
+                    "Project {} removed; could not confirm these Docker resources were removed \
+                     ({:?}), and the pending-cleanup record could not be written ({}) — nothing \
+                     will retry removing them",
+                    project_id, report, e
+                );
+            }
+        }
+    }
+
+    // The pending-cleanup record above must not outlive the project record it
+    // describes: if the store's own write fails (full disk, permissions) the
+    // project is still on disk and will reload on the next launch, but the
+    // record would tell startup housekeeping to delete its container and
+    // volumes out from under it. Roll the record back rather than leaving
+    // that mismatch for the retry to discover the hard way.
+    //
+    // This is a second, narrower line of defence, not the only one — a crash
+    // between the `save` above and the `remove` below leaves exactly the same
+    // mismatch with no error for either side to catch, which is why
+    // `retry_pending_cleanup_logged` also refuses to act on a record whose
+    // project is still listed in `projects.json`. Belt and suspenders: a
+    // caught failure here is handled immediately rather than waiting for the
+    // next launch to notice.
+    if let Err(e) = state.projects_store.remove(&project_id) {
+        if !report.is_clean() {
+            if let Err(clear_err) = crate::storage::pending_cleanup::clear(&project_id) {
+                log::error!(
+                    "Project {} was not removed ({}), and its pending-cleanup record could not \
+                     be rolled back either ({}) — it will name this still-live project until \
+                     startup housekeeping's own guard clears it",
+                    project_id, e, clear_err
+                );
+            }
+        }
+        return Err(e);
+    }
+    Ok(report)
+}
+
+/// Retry every pending-cleanup record left behind by a [`remove_project`]
+/// that could not finish. Run once at startup alongside the other reapers
+/// (see `lib.rs`'s "Startup disk housekeeping" block) — never on a timer and
+/// never blocking anything, since a locked volume or an in-use image can sit
+/// unresolved for an arbitrary amount of time and the daemon may not even be
+/// up yet.
+///
+/// Not a `#[tauri::command]`: nothing in the UI surfaces this list yet
+/// (deliberately — see `SnapshotSweepReport`'s doc comment for the same
+/// reasoning), so there is no IPC contract to keep. A record that still has
+/// leftovers after this is written back so the next run does not lose track
+/// of what changed; one that is now empty is deleted.
+///
+/// Takes the `ProjectsStore` so it can refuse to touch a project that is
+/// still live: `remove_project` writes a pending-cleanup record durably
+/// (fsync'd) *before* it asks the store to drop the project, and that
+/// store write is a plain `fs::write` with no fsync of its own. A crash or
+/// power loss in the gap between the two — or the store write failing
+/// outright, on top of the round-2 fix that only rolls the record back when
+/// that failure is caught in-process — can leave a record on disk pointing
+/// at a project `projects.json` still lists. Without this check, the very
+/// first retry after such a crash deletes that project's container,
+/// snapshot image and *both volumes, including the one holding the OAuth
+/// credential and every session transcript*, out from under a project the
+/// user still sees in the sidebar. A record whose project still exists is
+/// therefore always stale — cleared without touching Docker, not retried.
+pub async fn retry_pending_cleanup_logged(projects_store: &crate::storage::projects_store::ProjectsStore) {
+    let records = crate::storage::pending_cleanup::list();
+    if records.is_empty() {
+        return;
+    }
+
+    let mut cleaned = 0usize;
+    let mut still_pending = 0usize;
+
+    for mut record in records {
+        if projects_store.get(&record.project_id).is_some() {
+            log::warn!(
+                "Pending cleanup record for project {} ({}) names a project that still exists — \
+                 clearing the record without touching Docker rather than risk deleting a live \
+                 project's resources",
+                record.project_id, record.project_name
+            );
+            if let Err(e) = crate::storage::pending_cleanup::clear(&record.project_id) {
+                log::error!(
+                    "Could not clear the stale pending-cleanup record for still-live project {} \
+                     ({}): {}",
+                    record.project_id, record.project_name, e
+                );
+            }
+            continue;
+        }
+
+        if let Some(container_id) = record.container_id.take() {
+            match docker::remove_container(&container_id).await {
+                Ok(()) => {}
+                Err(e) => {
+                    log::warn!(
+                        "Pending cleanup: still could not remove container {} for project {} \
+                         ({}): {}",
+                        container_id, record.project_id, record.project_name, e
+                    );
+                    record.container_id = Some(container_id);
+                }
+            }
+        }
+
+        if let Some(image) = record.image.take() {
+            match docker::remove_image_by_name(&image).await {
+                Ok(()) => {}
+                Err(e) => {
+                    log::warn!(
+                        "Pending cleanup: still could not remove image {} for project {} ({}): {}",
+                        image, record.project_id, record.project_name, e
+                    );
+                    record.image = Some(image);
+                }
+            }
+        }
+
+        if !record.volumes.is_empty() {
+            record.volumes = docker::remove_volumes_by_name(&record.volumes).await;
+        }
+
+        if record.is_empty() {
+            if let Err(e) = crate::storage::pending_cleanup::clear(&record.project_id) {
+                log::warn!(
+                    "Pending cleanup for project {} ({}) finished but the record could not be \
+                     deleted: {}",
+                    record.project_id, record.project_name, e
+                );
+            }
+            cleaned += 1;
+        } else {
+            still_pending += 1;
+            // `recorded_at` is otherwise write-only — nothing read it back,
+            // which is exactly the shape `storage::migration_store` calls out
+            // as a bug in its own history ("nothing ever removed them"). A
+            // record that has failed every retry for a week is no longer
+            // routine: escalate the log level so it is not indistinguishable
+            // from one seen for the first time.
+            match pending_cleanup_is_stale(&record.recorded_at, chrono::Utc::now()) {
+                Some(true) => {
+                    log::error!(
+                        "Pending cleanup for project {} ({}) has not succeeded in over {} \
+                         days: {:?} — this may need a manual `docker volume rm` / \
+                         `docker rmi` / `docker rm`",
+                        record.project_id, record.project_name, PENDING_CLEANUP_STALE_AFTER_DAYS, record
+                    );
+                }
+                Some(false) => {}
+                // Silent otherwise would mean a record with a corrupted
+                // timestamp never escalates and nothing says why.
+                None => log::debug!(
+                    "Pending cleanup record for project {} ({}) has an unreadable recorded_at \
+                     ({:?}) — its age cannot be tracked",
+                    record.project_id, record.project_name, record.recorded_at
+                ),
+            }
+            if let Err(e) = crate::storage::pending_cleanup::save(&record) {
+                log::warn!(
+                    "Could not update pending cleanup record for project {} ({}): {}",
+                    record.project_id, record.project_name, e
+                );
+            }
+        }
+    }
+
+    log::info!(
+        "Pending cleanup retry: {} project(s) fully cleaned up, {} still have leftovers",
+        cleaned, still_pending
+    );
+}
+
+/// After this many days of a pending-cleanup record failing every retry,
+/// `retry_pending_cleanup_logged` escalates its log line from `warn` to
+/// `error` — see the comment at its call site.
+const PENDING_CLEANUP_STALE_AFTER_DAYS: i64 = 7;
+
+/// Whether a pending-cleanup record's `recorded_at` is older than
+/// [`PENDING_CLEANUP_STALE_AFTER_DAYS`], measured against `now`. `None` means
+/// the timestamp could not be parsed at all — a corrupted or (hypothetically)
+/// hand-edited record — which callers must not silently treat as "not stale"
+/// without saying why. `now` is a parameter rather than read internally so
+/// this is testable without a live clock.
+fn pending_cleanup_is_stale(recorded_at: &str, now: chrono::DateTime<chrono::Utc>) -> Option<bool> {
+    let recorded = chrono::DateTime::parse_from_rfc3339(recorded_at)
+        .ok()?
+        .with_timezone(&chrono::Utc);
+    Some(now.signed_duration_since(recorded) > chrono::Duration::days(PENDING_CLEANUP_STALE_AFTER_DAYS))
 }
 
 #[tauri::command]
@@ -1226,7 +1498,7 @@ pub async fn rebuild_project_container(
     project_id: String,
     app_handle: tauri::AppHandle,
     state: State<'_, AppState>,
-) -> Result<Project, String> {
+) -> Result<ProjectResetOutcome, String> {
     // Reset deletes both volumes and the snapshot image. Doing that while a
     // migration is mid-flight pulls the ground out from under it and leaves an
     // orphan migration record pointing at images that no longer exist — and
@@ -1253,25 +1525,58 @@ pub async fn rebuild_project_container(
     // `start_project_container` below re-arms it against the new one.
     state.auth_bridge.stop(&project_id).await;
 
-    // Remove existing container
-    if let Some(ref container_id) = project.container_id {
+    // Remove existing container. Resolved via `find_existing_container`
+    // unconditionally, not `project.container_id` — see the long comment in
+    // `remove_project` for why that field can be stale, not just absent. A
+    // container this misses blocks the volume removal immediately below with
+    // a 409, and Reset silently keeping the old volumes is exactly the bug
+    // this whole change is closing. Unlike `remove_project`'s best-effort
+    // handling of the same lookup failing, `?` here aborts Reset outright:
+    // every step after this one needs Docker too, so there is no useful
+    // partial progress to make without it.
+    // Closed for the stored id unconditionally, then again for the resolved
+    // one if it differs — see the matching comment in `remove_project` for
+    // why the stale-id race can leave sessions open under either identity.
+    if let Some(ref stored_id) = project.container_id {
+        state.exec_manager.close_sessions_for_container(stored_id).await;
+    }
+    let container_ref = docker::find_existing_container(&project).await?;
+    if let Some(ref container_id) = container_ref {
+        if project.container_id.as_deref() != Some(container_id.as_str()) {
             state.exec_manager.close_sessions_for_container(container_id).await;
+        }
         let _ = docker::stop_container(container_id).await;
         docker::remove_container(container_id).await?;
         state.projects_store.set_container_id(&project_id, None)?;
     }
 
-    // Remove snapshot image + volumes so Reset creates from the clean base image
+    // Remove snapshot image + volumes so Reset creates from the clean base
+    // image. Both leftovers are surfaced, not just logged — an image that
+    // survives is the more serious of the two, since
+    // `start_project_container_locked` below builds from
+    // `triple-c-snapshot-{id}:latest` whenever it exists, so a leftover image
+    // means Reset silently rebuilds the exact system layer it promised to
+    // discard. No pending-cleanup record for either: unlike `remove_project`,
+    // Reset keeps the project record, so a later Reset attempt can retry
+    // these itself rather than needing startup housekeeping to do it.
+    let mut leftover_image = None;
     if let Err(e) = docker::remove_snapshot_image(&project).await {
         log::warn!("Failed to remove snapshot image for project {}: {}", project_id, e);
+        leftover_image = Some(docker::get_snapshot_image_name(&project));
     }
-    if let Err(e) = docker::remove_project_volumes(&project).await {
-        log::warn!("Failed to remove project volumes for project {}: {}", project_id, e);
+    let leftover_volumes = docker::remove_project_volumes(&project).await;
+    if leftover_image.is_some() || !leftover_volumes.is_empty() {
+        log::warn!(
+            "Reset for project {} could not fully clean up — image: {:?}, volumes: {:?} — the \
+             new container may be built from, or reuse, old contents instead of starting clean",
+            project_id, leftover_image, leftover_volumes
+        );
     }
 
     // Start fresh. The locked variant, because `_guard` above is this project's
     // claim and the public command would be refused by it.
-    start_project_container_locked(project_id, app_handle, state).await
+    let project = start_project_container_locked(project_id, app_handle, state).await?;
+    Ok(ProjectResetOutcome { project, leftover_image, leftover_volumes })
 }
 
 /// Reconcile project statuses against actual Docker container state.
@@ -1379,6 +1684,54 @@ fn default_docker_socket() -> String {
 mod tests {
     use super::*;
 
+    // ── Pending-cleanup aging ────────────────────────────────────────────
+
+    #[test]
+    fn a_record_younger_than_the_threshold_is_not_stale() {
+        let now = "2026-08-25T00:00:00Z".parse().unwrap();
+        let recorded_at = "2026-08-19T00:00:00Z"; // 6 days before `now`
+        assert_eq!(pending_cleanup_is_stale(recorded_at, now), Some(false));
+    }
+
+    #[test]
+    fn a_record_exactly_at_the_threshold_is_not_yet_stale() {
+        let now = "2026-08-25T00:00:00Z".parse().unwrap();
+        let recorded_at = "2026-08-18T00:00:00Z"; // exactly 7 days before `now`
+        assert_eq!(
+            pending_cleanup_is_stale(recorded_at, now),
+            Some(false),
+            "the boundary itself must not already read as stale"
+        );
+    }
+
+    #[test]
+    fn a_record_older_than_the_threshold_is_stale() {
+        let now = "2026-08-25T00:00:00Z".parse().unwrap();
+        let recorded_at = "2026-08-17T00:00:00Z"; // 8 days before `now`
+        assert_eq!(pending_cleanup_is_stale(recorded_at, now), Some(true));
+    }
+
+    /// A clock that ran fast when the record was written leaves a timestamp
+    /// in the future. This must read as "not stale" rather than underflow or
+    /// panic — `signed_duration_since` returns a negative `Duration` here,
+    /// which compares less than any positive threshold correctly.
+    #[test]
+    fn a_timestamp_in_the_future_is_not_stale() {
+        let now = "2026-08-25T00:00:00Z".parse().unwrap();
+        let recorded_at = "2026-08-26T00:00:00Z"; // one day after `now`
+        assert_eq!(pending_cleanup_is_stale(recorded_at, now), Some(false));
+    }
+
+    /// A corrupted or hand-edited `recorded_at` must not silently read as
+    /// "not stale" through some default — callers need to be able to tell
+    /// "definitely not stale" apart from "cannot tell".
+    #[test]
+    fn an_unparseable_recorded_at_reports_unknown_rather_than_not_stale() {
+        let now = "2026-08-25T00:00:00Z".parse().unwrap();
+        assert_eq!(pending_cleanup_is_stale("not a timestamp", now), None);
+        assert_eq!(pending_cleanup_is_stale("", now), None);
+    }
+
     fn path(host: &str, mount: &str) -> ProjectPath {
         ProjectPath {
             host_path: host.to_string(),

app/src-tauri/src/commands/settings_commands.rs

@@ -10,19 +10,24 @@ pub async fn get_settings(state: State<'_, AppState>) -> Result<AppSettings, Str
     Ok(state.settings_store.get())
 }
 
-#[tauri::command]
-pub async fn update_settings(
-    settings: AppSettings,
-    state: State<'_, AppState>,
-) -> Result<AppSettings, String> {
-    let before = state.settings_store.get();
-
+/// Everything `update_settings` refuses a save over, run against the store's
+/// *current* value and the incoming one.
+///
+/// Pulled out so a caller that does other, harder-to-undo work alongside a
+/// settings save — `settings_export_commands::apply_settings_import`
+/// restores three keychain secrets in the same command — can run this
+/// *first* and bail before touching anything, rather than discovering the
+/// rejection only when `update_settings` itself runs partway through.
+pub fn validate_settings_update(
+    before: &AppSettings,
+    incoming: &AppSettings,
+) -> Result<(), String> {
     // The global half of the same rule the project half gets in
     // `update_project`: a global custom env var is merged into every project's
     // container environment, so an unchecked name here reaches all of them.
     crate::models::validate_env_vars_update(
         &before.global_custom_env_vars,
-        &settings.global_custom_env_vars,
+        &incoming.global_custom_env_vars,
     )?;
 
     // The same for the two host paths this struct owns. `update_project`
@@ -40,14 +45,37 @@ pub async fn update_settings(
     crate::commands::project_commands::validate_mounted_host_path(
         "SSH key path",
         before.default_ssh_key_path.as_deref(),
-        settings.default_ssh_key_path.as_deref(),
+        incoming.default_ssh_key_path.as_deref(),
     )?;
     crate::commands::project_commands::validate_mounted_host_path(
         "CA certificate path",
         before.ca_cert_path.as_deref(),
-        settings.ca_cert_path.as_deref(),
+        incoming.ca_cert_path.as_deref(),
     )?;
 
+    // Third host path this struct owns, same reasoning: any project with
+    // `allow_docker_access` bind-mounts this path in as the Docker socket
+    // (`project_commands.rs`'s container creation), so an unchecked value
+    // here is a read-write bind mount of whatever it names into every such
+    // project's container.
+    crate::commands::project_commands::validate_mounted_host_path(
+        "Docker socket path",
+        before.docker_socket_path.as_deref(),
+        incoming.docker_socket_path.as_deref(),
+    )?;
+
+    Ok(())
+}
+
+#[tauri::command]
+pub async fn update_settings(
+    settings: AppSettings,
+    state: State<'_, AppState>,
+) -> Result<AppSettings, String> {
+    let before = state.settings_store.get();
+
+    validate_settings_update(&before, &settings)?;
+
     let saved = state.settings_store.update(settings)?;
 
     // Persisting a setting is not the same as applying it. The gateway is the
@@ -122,7 +150,10 @@ async fn reconcile_gateway(before: &GatewaySettings, after: &GatewaySettings) {
         GatewayAction::StopIfRunning => {
             log::info!("Model gateway disabled in settings — stopping the container");
             if let Err(e) = docker::gateway::stop_gateway_container().await {
-                log::error!("Failed to stop the model gateway after it was disabled: {}", e);
+                log::error!(
+                    "Failed to stop the model gateway after it was disabled: {}",
+                    e
+                );
             }
         }
         GatewayAction::RestartIfRunning => {
@@ -138,10 +169,7 @@ async fn reconcile_gateway(before: &GatewaySettings, after: &GatewaySettings) {
 }
 
 #[tauri::command]
-pub async fn pull_image(
-    image_name: String,
-    app_handle: tauri::AppHandle,
-) -> Result<(), String> {
+pub async fn pull_image(image_name: String, app_handle: tauri::AppHandle) -> Result<(), String> {
     use tauri::Emitter;
     docker::pull_image(&image_name, move |msg| {
         let _ = app_handle.emit("image-pull-progress", msg);
@@ -334,7 +362,10 @@ mod tests {
         let before = enabled_gateway();
         let mut after = before.clone();
         after.enabled = false;
-        assert_eq!(gateway_action(&before, &after), GatewayAction::StopIfRunning);
+        assert_eq!(
+            gateway_action(&before, &after),
+            GatewayAction::StopIfRunning
+        );
         // Still true when it was already off — a stray running container is
         // still a container that shouldn't be up.
         assert_eq!(gateway_action(&after, &after), GatewayAction::StopIfRunning);

app/src-tauri/src/commands/settings_export_commands.rs

@@ -0,0 +1,654 @@
+//! Settings export/import — see triple-c#35.
+//!
+//! Exports the *host* environment (global `AppSettings` plus the global
+//! secrets kept in the OS keychain: the shared Claude Code OAuth login and
+//! the model gateway's two keys), encrypted with a user-chosen password —
+//! see `storage::settings_crypto` for the actual cryptography. Deliberately
+//! out of scope: per-project settings, per-project secrets, and anything
+//! living in a project's Docker volumes.
+//!
+//! **The save/open dialogs are opened from Rust**, the same pattern
+//! `file_commands.rs`'s `pick_save_path`/`pick_files_to_upload` already
+//! establish and document at length: a frontend-driven dialog handing Rust a
+//! host path string is the exact shape of bug that produced this app's past
+//! criticals, so the boundary here is drawn the same place. The frontend can
+//! ask for a picker; it cannot name a host path as an *input*. `preview_
+//! settings_import` resolves the chosen path itself and remembers it
+//! (`AppState::pending_settings_import`) so `apply_settings_import` re-reads
+//! the same file without the path ever crossing back over IPC.
+//!
+//! The *decrypted payload* is not cached between preview and apply — the
+//! password the frontend passes to each call is what it already held for
+//! the first, not a fresh secret extracted from the user, but nothing here
+//! keeps the plaintext itself — export/import secrets included — around for
+//! longer than one command's execution; `apply_settings_import` re-decrypts
+//! the file rather than reusing anything `preview_settings_import` computed.
+//!
+//! **This is new attack surface**: a settings export is a file one person
+//! can hand another and ask them to import, together with a password, and
+//! `apply_settings_import` applies whatever `AppSettings` it decrypts to
+//! wholesale — see the module doc on `models::settings_export` for the
+//! `web_terminal.access_token` carve-out a review of this feature found,
+//! and treat that as the standing example of the class of thing to keep
+//! checking for here, not a one-off fixed bug.
+
+#[cfg(test)]
+use std::path::Path;
+use std::path::PathBuf;
+
+use sha2::{Digest, Sha256};
+use tauri::State;
+use tauri_plugin_dialog::DialogExt;
+use zeroize::Zeroizing;
+
+use crate::models::{
+    AppSettings, ExportedSecrets, SettingsExportPayload, SettingsImportOutcome,
+    SettingsImportPreview, SETTINGS_EXPORT_FORMAT_VERSION,
+};
+use crate::storage::{secure, settings_crypto};
+use crate::AppState;
+
+/// What `preview_settings_import` pins so `apply_settings_import` can tell
+/// whether the file it's about to re-read is the same one the user actually
+/// saw a preview of. Confirming a preview is only meaningful if it's binding
+/// on what gets applied — without this, a file replaced on disk between the
+/// two calls (this app's own stated threat model is a file shared between
+/// people, which may sit in a synced or shared directory) would decrypt and
+/// apply silently different content than what the confirmation dialog showed.
+#[derive(Debug, Clone)]
+pub struct PendingSettingsImport {
+    path: PathBuf,
+    ciphertext_hash: [u8; 32],
+}
+
+fn hash_ciphertext(data: &[u8]) -> [u8; 32] {
+    Sha256::digest(data).into()
+}
+
+const FILE_EXTENSION: &str = "triplec";
+
+/// Enforced here, not only in the export modal: the frontend's minimum is a
+/// UX nudge, but `export_settings` is the actual boundary a weak password
+/// has to cross, and Argon2id's memory-hardness buys little against an
+/// attacker who can just try a three-character password directly.
+const MIN_PASSWORD_LEN: usize = 8;
+
+fn suggested_export_name() -> String {
+    // Timestamped so exporting more than once doesn't silently overwrite an
+    // earlier file just because the save dialog defaults to the same name.
+    format!(
+        "triple-c-settings-{}.{}",
+        chrono::Utc::now().format("%Y%m%d-%H%M%S"),
+        FILE_EXTENSION
+    )
+}
+
+async fn pick_export_save_path(window: &tauri::Window, suggested: &str) -> Option<PathBuf> {
+    let (tx, rx) = tokio::sync::oneshot::channel();
+    window
+        .dialog()
+        .file()
+        .set_parent(window)
+        .set_title("Export Triple-C settings")
+        .set_file_name(suggested)
+        .add_filter("Triple-C settings export", &[FILE_EXTENSION])
+        .save_file(move |picked| {
+            let _ = tx.send(picked);
+        });
+    rx.await.ok().flatten().and_then(|p| p.into_path().ok())
+}
+
+async fn pick_import_open_path(window: &tauri::Window) -> Option<PathBuf> {
+    let (tx, rx) = tokio::sync::oneshot::channel();
+    window
+        .dialog()
+        .file()
+        .set_parent(window)
+        .set_title("Import Triple-C settings")
+        .add_filter("Triple-C settings export", &[FILE_EXTENSION])
+        .pick_file(move |picked| {
+            let _ = tx.send(picked);
+        });
+    rx.await.ok().flatten().and_then(|p| p.into_path().ok())
+}
+
+/// Gather the current global secrets, and hand back the `AppSettings` to
+/// export with the web-terminal token blanked out of it — see the module
+/// doc comment on `models::settings_export` for why that field cannot
+/// travel through `settings` like the rest of this struct.
+///
+/// A missing keychain secret reads as `None` — a keychain read failure is
+/// treated as "nothing to export" for that one entry rather than aborting
+/// the whole export, matching how the rest of this app degrades a keychain
+/// error to "absent" (`has_claude_oauth_token`, `has_gateway_api_key`)
+/// rather than surfacing it as a hard failure.
+fn split_settings_and_secrets(current: AppSettings) -> (AppSettings, ExportedSecrets) {
+    let mut settings = current;
+    let web_terminal_access_token = settings.web_terminal.access_token.take();
+
+    let secrets = ExportedSecrets {
+        claude_oauth_token: secure::get_claude_oauth_token().unwrap_or_default(),
+        gateway_api_key: secure::get_gateway_api_key().unwrap_or_default(),
+        gateway_master_key: secure::get_gateway_master_key().unwrap_or_default(),
+        web_terminal_access_token,
+    };
+
+    (settings, secrets)
+}
+
+/// Export the current global settings and secrets to a password-encrypted
+/// file. `Ok(false)` means the save dialog was dismissed — not an error, and
+/// deliberately distinguishable from one so the frontend shows nothing
+/// rather than a "failed" toast for a plain cancel.
+#[tauri::command]
+pub async fn export_settings(
+    password: String,
+    window: tauri::Window,
+    state: State<'_, AppState>,
+) -> Result<bool, String> {
+    // `.chars().count()` — Unicode scalar values, not bytes — to stay as
+    // close as this pair of languages allows to the frontend's `.length`
+    // check (UTF-16 code units); the two only diverge on astral-plane
+    // characters, which no reasonable password touches.
+    if password.chars().count() < MIN_PASSWORD_LEN {
+        return Err(format!(
+            "Use a password of at least {} characters.",
+            MIN_PASSWORD_LEN
+        ));
+    }
+
+    let Some(dest) = pick_export_save_path(&window, &suggested_export_name()).await else {
+        return Ok(false);
+    };
+
+    let (settings, secrets) = split_settings_and_secrets(state.settings_store.get());
+    if secrets.is_empty() {
+        log::info!("Exporting settings with no global secrets configured on this machine");
+    }
+
+    let payload = SettingsExportPayload {
+        format_version: SETTINGS_EXPORT_FORMAT_VERSION,
+        exported_at: chrono::Utc::now().to_rfc3339(),
+        app_version: env!("CARGO_PKG_VERSION").to_string(),
+        settings,
+        secrets,
+    };
+
+    let plaintext = Zeroizing::new(
+        serde_json::to_vec(&payload)
+            .map_err(|e| format!("Failed to prepare settings for export: {}", e))?,
+    );
+    let encrypted = settings_crypto::encrypt(&plaintext, &password)?;
+
+    std::fs::write(&dest, &encrypted).map_err(|e| format!("Failed to write export file: {}", e))?;
+
+    Ok(true)
+}
+
+/// Open a file picker, decrypt the chosen file with `password`, and return a
+/// preview (counts and presence flags only — never a secret value) for a
+/// confirmation UI. `Ok(None)` means the picker was dismissed.
+///
+/// Remembers the resolved path *and a hash of the file's ciphertext* in
+/// `AppState::pending_settings_import` for `apply_settings_import` to check
+/// against — does **not** remember the decrypted payload itself, so the
+/// password must be supplied again to actually apply it — seeing the preview
+/// is not the same as committing to it. The hash exists so it also can't be
+/// swapped out from under that commitment: `apply_settings_import` refuses to
+/// proceed if the file on disk no longer matches what was just previewed.
+#[tauri::command]
+pub async fn preview_settings_import(
+    password: String,
+    window: tauri::Window,
+    state: State<'_, AppState>,
+) -> Result<Option<SettingsImportPreview>, String> {
+    if password.is_empty() {
+        return Err("A password is required to open a settings export.".to_string());
+    }
+
+    let Some(path) = pick_import_open_path(&window).await else {
+        return Ok(None);
+    };
+
+    let encrypted = std::fs::read(&path).map_err(|e| format!("Failed to read export file: {}", e))?;
+    let payload = read_and_decrypt_bytes(&encrypted, &password)?;
+    let preview = SettingsImportPreview::from_payload(&payload);
+
+    *state.pending_settings_import.lock().await = Some(PendingSettingsImport {
+        path,
+        ciphertext_hash: hash_ciphertext(&encrypted),
+    });
+
+    Ok(Some(preview))
+}
+
+/// Apply the import a prior `preview_settings_import` call resolved a path
+/// for. Fails if no preview is pending — this is not a general "decrypt and
+/// apply this file" entry point, deliberately: seeing the preview first is
+/// required, not just encouraged, since it is the only place a user is told
+/// what an import is about to touch before it touches it. That requirement
+/// is only real if the file can't change out from under it, so this also
+/// refuses to proceed if the file's ciphertext no longer matches the hash
+/// `preview_settings_import` pinned — a file replaced on disk between the
+/// two calls (this feature's own threat model is a file shared between
+/// people, which may sit in a synced or shared directory) must not be able
+/// to apply silently different content than what the confirmation dialog
+/// showed.
+///
+/// Global settings are replaced wholesale — an import is "restore this
+/// environment," not a field-by-field merge. Global secrets are handled
+/// differently and on purpose: **only secrets actually present in the
+/// import are written**; a secret the export doesn't have is left alone on
+/// this machine rather than cleared, because an absent secret in the export
+/// means "the source machine never had this configured," not "delete this
+/// on import." A user who wants to clear a secret already has dedicated UI
+/// for that (signing out of shared auth, clearing the gateway key).
+///
+/// Order matters here, twice over.
+///
+/// First: the imported settings are **validated before any secret is
+/// written**, using the same checks `update_settings` itself runs
+/// (`settings_commands::validate_settings_update`). Restoring a secret is
+/// hard to undo unnoticed — a stale env-var-name rejection or a disallowed
+/// host path used to be caught only when `update_settings` ran, by which
+/// point the three keychain secrets below were already overwritten with the
+/// file's, each with a fresh rotation id, silently flagging every project
+/// container for recreation — while the error the user saw talked only
+/// about the rejected setting and said nothing about the credentials that
+/// had already moved. Failing this check first makes a rejected import
+/// leave nothing touched, matching what "the import failed" is supposed to
+/// mean.
+///
+/// Second, among the things that *do* get written: secrets are restored
+/// **before** the settings replace runs (which is what triggers
+/// `reconcile_gateway`), so a gateway recreation that replace provokes sees
+/// the final key material rather than racing it — restoring the other way
+/// round left a real window where the running gateway and the keychain
+/// briefly disagreed. A gateway *secret* alone (same shape, new key) is
+/// invisible to `reconcile_gateway`'s shape comparison, so this additionally
+/// nudges a running gateway container to recreate itself whenever a secret
+/// this import carried was actually written — otherwise the running
+/// container keeps serving the old key material indefinitely while every
+/// project container is handed the new one.
+///
+/// A keychain write failing is reported back rather than only logged: an
+/// import that silently restores two of three secrets but not the third
+/// must not read as unqualified success.
+///
+/// The pending import is only cleared on success. A failure here (rejected
+/// by the validation above, a stale-file mismatch, or some other error)
+/// leaves it pending so the frontend can let the user retry `apply` without
+/// making them pick the file and re-enter the password again — the
+/// preview's job was confirming *what* to import, not spending the one
+/// attempt at applying it.
+#[tauri::command]
+pub async fn apply_settings_import(
+    password: String,
+    state: State<'_, AppState>,
+) -> Result<SettingsImportOutcome, String> {
+    if password.is_empty() {
+        return Err("A password is required to import settings.".to_string());
+    }
+
+    let pending = state
+        .pending_settings_import
+        .lock()
+        .await
+        .clone()
+        .ok_or_else(|| "No import is pending — choose a file first.".to_string())?;
+
+    let encrypted = std::fs::read(&pending.path)
+        .map_err(|e| format!("Failed to read export file: {}", e))?;
+    if hash_ciphertext(&encrypted) != pending.ciphertext_hash {
+        return Err(
+            "This file changed since you reviewed it — choose it again to see an up-to-date preview."
+                .to_string(),
+        );
+    }
+    let payload = read_and_decrypt_bytes(&encrypted, &password)?;
+
+    let current = state.settings_store.get();
+
+    // The web-terminal token lives inside `AppSettings` itself rather than
+    // the keychain, so "leave an absent secret alone" has to be done by
+    // hand here: carry the destination's current token forward when the
+    // import doesn't have one, instead of letting the wholesale replace
+    // below blank it (every export writes `None` there — see
+    // `split_settings_and_secrets`).
+    let mut settings = payload.settings;
+    settings.web_terminal.access_token = non_blank(payload.secrets.web_terminal_access_token)
+        .or_else(|| current.web_terminal.access_token.clone());
+
+    crate::commands::settings_commands::validate_settings_update(&current, &settings)?;
+
+    let mut secret_restore_warnings = Vec::new();
+    let mut gateway_secret_changed = false;
+
+    if let Some(token) = non_blank(payload.secrets.claude_oauth_token) {
+        if let Err(e) = secure::store_claude_oauth_token(&token) {
+            log::warn!(
+                "Settings import: could not restore the shared Claude login: {}",
+                e
+            );
+            secret_restore_warnings
+                .push(format!("Could not restore your shared Claude login: {}", e));
+        }
+    }
+    if let Some(key) = non_blank(payload.secrets.gateway_api_key) {
+        match secure::store_gateway_api_key(&key) {
+            Ok(()) => gateway_secret_changed = true,
+            Err(e) => {
+                log::warn!(
+                    "Settings import: could not restore the gateway provider API key: {}",
+                    e
+                );
+                secret_restore_warnings.push(format!(
+                    "Could not restore the gateway provider API key: {}",
+                    e
+                ));
+            }
+        }
+    }
+    if let Some(key) = non_blank(payload.secrets.gateway_master_key) {
+        match secure::store_gateway_master_key(&key) {
+            Ok(()) => gateway_secret_changed = true,
+            Err(e) => {
+                log::warn!(
+                    "Settings import: could not restore the gateway master key: {}",
+                    e
+                );
+                secret_restore_warnings
+                    .push(format!("Could not restore the gateway master key: {}", e));
+            }
+        }
+    }
+
+    let saved =
+        crate::commands::settings_commands::update_settings(settings, state.clone()).await?;
+
+    // `reconcile_gateway` (inside `update_settings`) only reacts to a changed
+    // *shape* — port, provider, base URL, models — because that's what's
+    // rendered into the container's config. A secret changing with the shape
+    // held constant is invisible to it, so a running gateway container would
+    // otherwise keep serving the old key material forever after an import
+    // that restored a new one, while `docker::gateway`'s own fingerprint
+    // (which does include the secret rotation id) means the *next* unrelated
+    // settings save would suddenly and confusingly recreate it instead.
+    if gateway_secret_changed && saved.gateway.enabled {
+        match crate::docker::gateway::gateway_container_presence().await {
+            Ok((true, true)) => {
+                if let Err(e) = crate::docker::gateway::ensure_gateway_running(&saved.gateway).await
+                {
+                    log::error!(
+                        "Settings import: could not apply the restored gateway credentials to the running gateway container: {}",
+                        e
+                    );
+                }
+            }
+            Ok(_) => {}
+            Err(e) => log::debug!("Settings import: gateway reconcile skipped ({})", e),
+        }
+    }
+
+    state.pending_settings_import.lock().await.take();
+
+    Ok(SettingsImportOutcome {
+        settings: saved,
+        secret_restore_warnings,
+    })
+}
+
+fn non_blank(value: Option<String>) -> Option<String> {
+    value.filter(|v| !v.trim().is_empty())
+}
+
+/// Only the field `read_and_decrypt` needs before deciding whether the rest
+/// of the payload is even worth attempting to parse.
+#[derive(serde::Deserialize)]
+struct FormatVersionProbe {
+    format_version: u32,
+}
+
+/// Read and decrypt an export file at `path`, then parse it — see
+/// `read_and_decrypt_bytes` for why the format-version check runs before the
+/// full parse. Every real caller already has the file's bytes in hand by the
+/// time it needs this (`preview_settings_import`/`apply_settings_import`
+/// both hash the ciphertext first) and calls `read_and_decrypt_bytes`
+/// directly to avoid reading the file twice; this path-based wrapper only
+/// exists now for tests that don't need that.
+#[cfg(test)]
+fn read_and_decrypt(path: &Path, password: &str) -> Result<SettingsExportPayload, String> {
+    let encrypted =
+        std::fs::read(path).map_err(|e| format!("Failed to read export file: {}", e))?;
+    read_and_decrypt_bytes(&encrypted, password)
+}
+
+/// Decrypt and parse an already-read export file's bytes, checking the
+/// format version **before** attempting to deserialize the full payload.
+///
+/// That ordering is not just tidiness: a version bump that isn't
+/// deserialize-compatible (a field's type changes, not just a new
+/// `#[serde(default)]`-covered one) is exactly the case this check exists
+/// for, and parsing the full struct first would fail on the shape mismatch
+/// before the version check ever ran, surfacing a raw parse error instead
+/// of "update Triple-C" — and, more seriously, `serde_json`'s type-mismatch
+/// errors quote the offending value inline. This file is not attacker
+/// content in the usual sense (it must still decrypt under the right
+/// password), but the plaintext it decrypts to can hold a live credential,
+/// so neither error path below ever interpolates what `serde_json`
+/// actually says — only a fixed, generic message.
+fn read_and_decrypt_bytes(encrypted: &[u8], password: &str) -> Result<SettingsExportPayload, String> {
+    let plaintext = settings_crypto::decrypt(encrypted, password)?;
+
+    let probe: FormatVersionProbe = serde_json::from_slice(&plaintext)
+        .map_err(|_| "This file doesn't look like a valid settings export.".to_string())?;
+    if probe.format_version > SETTINGS_EXPORT_FORMAT_VERSION {
+        return Err(format!(
+            "This export was made by a newer version of Triple-C (format {}, this app supports up to {}). \
+             Update Triple-C before importing it.",
+            probe.format_version, SETTINGS_EXPORT_FORMAT_VERSION
+        ));
+    }
+
+    serde_json::from_slice(&plaintext).map_err(|_| {
+        "This file doesn't look like a valid settings export (unexpected shape).".to_string()
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn non_blank_treats_whitespace_only_as_absent() {
+        assert_eq!(non_blank(Some("   ".to_string())), None);
+        assert_eq!(non_blank(Some("".to_string())), None);
+        assert_eq!(non_blank(None), None);
+        assert_eq!(non_blank(Some(" a ".to_string())), Some(" a ".to_string()));
+    }
+
+    #[test]
+    fn ciphertext_hashing_is_deterministic_and_tamper_sensitive() {
+        // What `apply_settings_import` compares against the pinned hash from
+        // `preview_settings_import` to detect a file swapped out from under a
+        // pending import — this only defends anything if identical bytes
+        // always hash identically and any change to those bytes changes the
+        // hash.
+        let bytes = b"pretend this is an encrypted export file";
+        assert_eq!(hash_ciphertext(bytes), hash_ciphertext(bytes));
+
+        let mut tampered = bytes.to_vec();
+        tampered[0] ^= 0xFF;
+        assert_ne!(hash_ciphertext(bytes), hash_ciphertext(&tampered));
+    }
+
+    fn write_export(
+        dir: &std::path::Path,
+        name: &str,
+        payload: &SettingsExportPayload,
+        password: &str,
+    ) -> PathBuf {
+        write_raw_export(dir, name, &serde_json::to_value(payload).unwrap(), password)
+    }
+
+    /// Like `write_export`, but takes an arbitrary `serde_json::Value` rather
+    /// than a real `SettingsExportPayload` — for fixtures that are
+    /// deliberately not shape-compatible, which the typed helper above can't
+    /// produce at all.
+    fn write_raw_export(
+        dir: &std::path::Path,
+        name: &str,
+        value: &serde_json::Value,
+        password: &str,
+    ) -> PathBuf {
+        let plaintext = serde_json::to_vec(value).unwrap();
+        let encrypted = settings_crypto::encrypt(&plaintext, password).unwrap();
+        let path = dir.join(name);
+        std::fs::write(&path, &encrypted).unwrap();
+        path
+    }
+
+    #[test]
+    fn splitting_settings_moves_the_web_terminal_token_out_rather_than_copying_it() {
+        let mut settings = AppSettings::default();
+        settings.web_terminal.access_token = Some("super-secret-token".to_string());
+
+        let (settings, secrets) = split_settings_and_secrets(settings);
+
+        assert_eq!(settings.web_terminal.access_token, None);
+        assert_eq!(
+            secrets.web_terminal_access_token,
+            Some("super-secret-token".to_string())
+        );
+    }
+
+    #[test]
+    fn splitting_settings_with_no_token_leaves_it_absent_on_both_sides() {
+        let (settings, secrets) = split_settings_and_secrets(AppSettings::default());
+
+        assert_eq!(settings.web_terminal.access_token, None);
+        assert_eq!(secrets.web_terminal_access_token, None);
+    }
+
+    fn sample_payload(format_version: u32) -> SettingsExportPayload {
+        SettingsExportPayload {
+            format_version,
+            exported_at: "2026-08-27T00:00:00Z".to_string(),
+            app_version: "0.4.14".to_string(),
+            settings: AppSettings::default(),
+            secrets: ExportedSecrets::default(),
+        }
+    }
+
+    fn temp_dir(name: &str) -> PathBuf {
+        let dir = std::env::temp_dir().join(format!(
+            "triple-c-settings-export-test-{}-{}",
+            name,
+            uuid::Uuid::new_v4().simple()
+        ));
+        std::fs::create_dir_all(&dir).unwrap();
+        dir
+    }
+
+    #[test]
+    fn a_file_from_a_newer_format_is_refused_before_the_full_shape_is_parsed() {
+        // Shape-incompatible with the *current* `SettingsExportPayload` (a
+        // future version could easily have changed `settings` from an object
+        // to something else) as well as newer — so this only passes under
+        // the probe-first ordering. Parsing the full struct first (the old
+        // behavior) would fail on the shape mismatch and never reach the
+        // version check, producing the "unexpected shape" message instead of
+        // "newer version" / "Update Triple-C".
+        let dir = temp_dir("newer-format");
+        let path = write_raw_export(
+            &dir,
+            "export.triplec",
+            &serde_json::json!({
+                "format_version": SETTINGS_EXPORT_FORMAT_VERSION + 1,
+                "exported_at": "2026-08-27T00:00:00Z",
+                "app_version": "9.9.9",
+                "settings": "this-app-version-stores-settings-differently",
+                "secrets": {},
+            }),
+            "correct password",
+        );
+
+        let err = read_and_decrypt(&path, "correct password").unwrap_err();
+        assert!(err.contains("newer version"), "unexpected message: {}", err);
+        assert!(err.contains("Update Triple-C"));
+
+        std::fs::remove_dir_all(&dir).ok();
+    }
+
+    #[test]
+    fn a_file_at_the_current_format_is_accepted() {
+        let dir = temp_dir("current-format");
+        let path = write_export(
+            &dir,
+            "export.triplec",
+            &sample_payload(SETTINGS_EXPORT_FORMAT_VERSION),
+            "correct password",
+        );
+
+        let payload = read_and_decrypt(&path, "correct password").unwrap();
+        assert_eq!(payload.format_version, SETTINGS_EXPORT_FORMAT_VERSION);
+
+        std::fs::remove_dir_all(&dir).ok();
+    }
+
+    #[test]
+    fn a_malformed_payload_produces_a_generic_error_not_a_raw_serde_message() {
+        // A `format_version` the probe accepts, but a `settings` field of
+        // the wrong *type* rather than just a missing field — this is what
+        // makes `serde_json` produce an "invalid type: string `...`, expected
+        // struct AppSettings" error that quotes the offending value
+        // verbatim. That value here stands in for plaintext that, in a real
+        // export, could be a live credential — the assertion below is only
+        // meaningful against a fixture that actually exercises serde's
+        // value-quoting behavior, which a merely-missing-field fixture does
+        // not.
+        let dir = temp_dir("malformed");
+        let path = write_raw_export(
+            &dir,
+            "export.triplec",
+            &serde_json::json!({
+                "format_version": SETTINGS_EXPORT_FORMAT_VERSION,
+                "exported_at": "2026-08-27T00:00:00Z",
+                "app_version": "0.4.14",
+                "settings": "NOT-A-REAL-CREDENTIAL-abc123",
+                "secrets": {},
+            }),
+            "correct password",
+        );
+
+        let err = read_and_decrypt(&path, "correct password").unwrap_err();
+        assert!(
+            !err.contains("NOT-A-REAL-CREDENTIAL-abc123"),
+            "leaked plaintext into the error: {}",
+            err
+        );
+        assert!(err.contains("doesn't look like a valid settings export"));
+
+        std::fs::remove_dir_all(&dir).ok();
+    }
+
+    #[test]
+    fn the_wrong_password_is_reported_without_a_version_check_ever_running() {
+        let dir = temp_dir("wrong-password");
+        let path = write_export(
+            &dir,
+            "export.triplec",
+            &sample_payload(SETTINGS_EXPORT_FORMAT_VERSION),
+            "correct password",
+        );
+
+        let err = read_and_decrypt(&path, "wrong password").unwrap_err();
+        assert!(
+            err.contains("Wrong password"),
+            "unexpected message: {}",
+            err
+        );
+
+        std::fs::remove_dir_all(&dir).ok();
+    }
+}

app/src-tauri/src/commands/terminal_commands.rs

@@ -202,8 +202,11 @@ pub async fn upload_host_file_to_terminal(
     // (`~/.ssh`, `~/.aws`, `~/.local/bin`) or a system location — applied to
     // the path with its symlinks already resolved, so a visible directory that
     // *leads* to one of those is refused too. What comes back is that resolved
-    // path, and it is what gets opened. This is now one of only two commands
-    // that touch a host path at all; the other is `download_container_backup`.
+    // path, and it is what gets opened. Four commands touch a host path now,
+    // but only two take it *over IPC*: this one and `download_container_backup`.
+    // The Files pane's `download_container_file` and `upload_files_to_container`
+    // open their dialog from Rust instead, so for them the policy above is
+    // defence in depth and for these two it is the boundary itself.
     // The name is taken from the path the user actually dropped, *before*
     // resolution. Deriving it from the resolved path renames the file behind
     // the user's back: dropping `~/Downloads/latest.log`, where `latest.log` is
@@ -222,8 +225,9 @@ pub async fn upload_host_file_to_terminal(
     // with no writer, with no timeout anywhere on this path. The upload then
     // never returns, the toast sticks on "Adding N files…" for the session and
     // the rest of the batch is abandoned. Sockets and device nodes are the same
-    // shape. With the Files tab's upload removed, this is the only route for
-    // getting a file into a container, so it is the wrong place to be clever.
+    // shape. This is one of two routes for getting a host file into a
+    // container (the Files pane's upload is the other), so it is the wrong
+    // place to be clever.
     if !meta.is_file() {
         return Err(if meta.is_dir() {
             format!("{} is a directory — drop individual files", host_path)
@@ -260,7 +264,13 @@ pub async fn upload_host_file_to_terminal(
     .await?;
 
     let file_name = format!("triple-c-drops/{}", base);
-    crate::docker::exec::upload_host_file_to_container(&container_id, &host_path, &file_name).await
+    crate::docker::exec::upload_host_file_to_container(
+        &container_id,
+        &host_path,
+        "/tmp",
+        &file_name,
+    )
+    .await
 }
 
 #[tauri::command]

app/src-tauri/src/commands/update_commands.rs

@@ -16,9 +16,37 @@ const REGISTRY_API_BASE: &str =
 const GHCR_TOKEN_URL: &str =
     "https://ghcr.io/token?scope=repository:shadowdao/triple-c-sandbox:pull";
 
+/// The build-time preview suffix, if one was baked in and isn't blank.
+///
+/// The bundle version itself (`tauri.conf.json`, `Cargo.toml`, `package.json`)
+/// is never given a `-preview.<sha>` suffix — `build-app-preview.yml` strips
+/// it before patching those files, because the Windows MSI's `ProductVersion`
+/// is a fixed-width numeric field with no room for one, and nothing here can
+/// verify a change to that without an actual Windows build. `TRIPLE_C_BUILD_SUFFIX`
+/// is the workaround: set as a build-time env var in the preview workflow
+/// only, so `option_env!` bakes it into the binary without the bundle version
+/// ever seeing it. A production build sets nothing, so `option_env!` reads
+/// `None` here — see triple-c#32.
+///
+/// The single source of truth for "is this a preview build": both
+/// `get_app_version()` (what the About panel shows) and `check_for_updates()`
+/// (whether a same-numbered release counts as an update — see `pick_update`)
+/// read this rather than each calling `option_env!` themselves, so the two
+/// can never silently disagree about which build this is.
+fn preview_build_suffix() -> Option<&'static str> {
+    option_env!("TRIPLE_C_BUILD_SUFFIX").filter(|s| !s.is_empty())
+}
+
+fn format_app_version(base: &str, build_suffix: Option<&str>) -> String {
+    match build_suffix {
+        Some(suffix) if !suffix.is_empty() => format!("{}-{}", base, suffix),
+        _ => base.to_string(),
+    }
+}
+
 #[tauri::command]
 pub fn get_app_version() -> String {
-    env!("CARGO_PKG_VERSION").to_string()
+    format_app_version(env!("CARGO_PKG_VERSION"), preview_build_suffix())
 }
 
 #[tauri::command]
@@ -51,30 +79,20 @@ pub async fn check_for_updates() -> Result<Option<UpdateInfo>, String> {
         &[".AppImage", ".deb", ".rpm"]
     };
 
-    // Filter releases that have at least one asset matching the current platform
-    let platform_releases: Vec<&GitHubRelease> = releases
-        .iter()
-        .filter(|r| {
-            r.assets.iter().any(|a| {
-                platform_extensions.iter().any(|ext| a.name.ends_with(ext))
-            })
-        })
-        .collect();
+    // `current_version` above is always the bare, stripped `CARGO_PKG_VERSION`
+    // — the preview workflow patches `Cargo.toml` with that before compiling,
+    // never the `-preview.<sha>`-suffixed one `get_app_version()` reports —
+    // so a preview build and the release it precedes compile to the identical
+    // numeric tuple by construction (see `build-app-preview.yml`'s "highest
+    // tag used, +1" computation). A strict `>` therefore never fires for the
+    // one release a preview most needs to be offered. `is_preview_build`
+    // relaxes that one comparison to `>=` so "there is a real release at my
+    // own number" reads as an update, without touching the production case
+    // — see `pick_update`.
+    let is_preview_build = preview_build_suffix().is_some();
 
-    // Find the latest release with a higher semver version
-    let mut best: Option<(&GitHubRelease, (u32, u32, u32))> = None;
-    for release in &platform_releases {
-        if let Some(ver) = parse_semver_from_tag(&release.tag_name) {
-            if ver > current_semver {
-                if best.is_none() || ver > best.unwrap().1 {
-                    best = Some((release, ver));
-                }
-            }
-        }
-    }
-
-    match best {
-        Some((release, _)) => {
+    match pick_update(&releases, current_semver, platform_extensions, is_preview_build) {
+        Some(release) => {
             // Only include assets matching the current platform
             let assets = release
                 .assets
@@ -105,6 +123,51 @@ pub async fn check_for_updates() -> Result<Option<UpdateInfo>, String> {
     }
 }
 
+/// Pick the newest available update out of a release list, or `None` if
+/// nothing beats `current_semver`. Pure and synchronous — split out of
+/// `check_for_updates` so the prerelease/platform/version filtering can be
+/// tested without a live HTTP call.
+///
+/// Three filters, all of which must pass: not a prerelease (see the long
+/// comment on `GitHubRelease::prerelease`), at least one asset for this
+/// platform, and a tag that parses as semver *and* beats what is running. A
+/// tag that does not parse — `preview-<sha>` (the shape
+/// `build-app-preview.yml` actually creates release tags with), most
+/// realistically — is skipped rather than erroring, the same as it always
+/// has been; nothing here changes what an update tag is expected to look
+/// like, only what channel it is allowed to come from.
+///
+/// `is_preview_build` relaxes "beats" from `>` to `>=`. A preview build's
+/// `current_semver` is the bare number it was compiled with, which is by
+/// construction identical to the release it precedes — see the comment at
+/// `check_for_updates`'s call site — so a strict `>` would never fire for
+/// exactly the release a preview install most needs to be told about.
+fn pick_update<'a>(
+    releases: &'a [GitHubRelease],
+    current_semver: (u32, u32, u32),
+    platform_extensions: &[&str],
+    is_preview_build: bool,
+) -> Option<&'a GitHubRelease> {
+    releases
+        .iter()
+        .filter(|r| !r.prerelease)
+        .filter(|r| {
+            r.assets
+                .iter()
+                .any(|a| platform_extensions.iter().any(|ext| a.name.ends_with(ext)))
+        })
+        .filter_map(|r| parse_semver_from_tag(&r.tag_name).map(|ver| (r, ver)))
+        .filter(|(_, ver)| {
+            if is_preview_build {
+                *ver >= current_semver
+            } else {
+                *ver > current_semver
+            }
+        })
+        .max_by_key(|(_, ver)| *ver)
+        .map(|(r, _)| r)
+}
+
 /// Parse a semver string like "0.2.5" -> (0, 2, 5)
 fn parse_semver(version: &str) -> Option<(u32, u32, u32)> {
     let clean = version.trim_start_matches('v');
@@ -131,6 +194,120 @@ fn extract_version_from_tag(tag: &str) -> Option<String> {
     Some(format!("{}.{}.{}", major, minor, patch))
 }
 
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::models::GitHubAsset;
+
+    // ── format_app_version ──────────────────────────────────────────────
+
+    #[test]
+    fn a_production_build_reports_the_bare_version() {
+        assert_eq!(format_app_version("0.4.12", None), "0.4.12");
+        // An empty env var (set but blank) must not print a trailing dash.
+        assert_eq!(format_app_version("0.4.12", Some("")), "0.4.12");
+    }
+
+    #[test]
+    fn a_preview_build_reports_its_suffix() {
+        assert_eq!(
+            format_app_version("0.4.12", Some("preview.a1b2c3d")),
+            "0.4.12-preview.a1b2c3d"
+        );
+    }
+
+    // ── pick_update ──────────────────────────────────────────────────────
+
+    fn release(tag: &str, prerelease: bool, asset_names: &[&str]) -> GitHubRelease {
+        GitHubRelease {
+            tag_name: tag.to_string(),
+            html_url: format!("https://example.invalid/{}", tag),
+            body: String::new(),
+            assets: asset_names
+                .iter()
+                .map(|name| GitHubAsset {
+                    name: name.to_string(),
+                    browser_download_url: String::new(),
+                    size: 0,
+                })
+                .collect(),
+            published_at: "2026-01-01T00:00:00Z".to_string(),
+            prerelease,
+        }
+    }
+
+    const LINUX_EXTENSIONS: &[&str] = &[".AppImage", ".deb", ".rpm"];
+
+    #[test]
+    fn a_prerelease_is_never_offered_even_if_its_tag_would_otherwise_win() {
+        let releases = vec![release("v9.9.9", true, &["app-9.9.9.AppImage"])];
+        assert!(pick_update(&releases, (0, 4, 10), LINUX_EXTENSIONS, false).is_none());
+    }
+
+    #[test]
+    fn a_release_with_no_asset_for_this_platform_is_skipped() {
+        let releases = vec![release("v0.4.12", false, &["app-0.4.12.msi"])];
+        assert!(pick_update(&releases, (0, 4, 10), LINUX_EXTENSIONS, false).is_none());
+    }
+
+    #[test]
+    fn a_release_that_is_not_newer_is_not_offered() {
+        let releases = vec![release("v0.4.10", false, &["app.AppImage"])];
+        assert!(pick_update(&releases, (0, 4, 10), LINUX_EXTENSIONS, false).is_none());
+    }
+
+    #[test]
+    fn an_untagged_or_unparseable_release_is_skipped_not_fatal() {
+        // A `-preview.<sha>` tag is exactly the shape this must not choke on
+        // or mistake for an update — it simply never parses as a bare semver.
+        let releases = vec![
+            release("preview-a1b2c3d", false, &["app.AppImage"]),
+            release("v0.4.12", false, &["app.AppImage"]),
+        ];
+        let best = pick_update(&releases, (0, 4, 10), LINUX_EXTENSIONS, false).unwrap();
+        assert_eq!(best.tag_name, "v0.4.12");
+    }
+
+    #[test]
+    fn the_highest_qualifying_version_wins_not_the_first_or_last_in_the_list() {
+        let releases = vec![
+            release("v0.4.11", false, &["app.AppImage"]),
+            release("v0.4.13", false, &["app.AppImage"]),
+            release("v0.4.12", false, &["app.AppImage"]),
+        ];
+        let best = pick_update(&releases, (0, 4, 10), LINUX_EXTENSIONS, false).unwrap();
+        assert_eq!(best.tag_name, "v0.4.13");
+    }
+
+    // ── is_preview_build (>= instead of >) ─────────────────────────────────
+
+    /// The exact scenario triple-c#32 was filed to fix: a preview compiled as
+    /// `0.4.12-preview.<sha>` (bare `CARGO_PKG_VERSION` "0.4.12") must be
+    /// offered the `v0.4.12` release that follows it, even though the two
+    /// compute to the identical numeric tuple.
+    #[test]
+    fn a_preview_build_is_offered_the_release_it_precedes() {
+        let releases = vec![release("v0.4.12", false, &["app.AppImage"])];
+        assert!(pick_update(&releases, (0, 4, 12), LINUX_EXTENSIONS, false).is_none());
+        let best = pick_update(&releases, (0, 4, 12), LINUX_EXTENSIONS, true).unwrap();
+        assert_eq!(best.tag_name, "v0.4.12");
+    }
+
+    #[test]
+    fn a_preview_build_is_not_offered_an_older_release() {
+        let releases = vec![release("v0.4.11", false, &["app.AppImage"])];
+        assert!(pick_update(&releases, (0, 4, 12), LINUX_EXTENSIONS, true).is_none());
+    }
+
+    #[test]
+    fn a_production_build_still_requires_strictly_newer() {
+        // A production build must never treat "equal" as an update — that
+        // would perpetually re-offer the version already running.
+        let releases = vec![release("v0.4.12", false, &["app.AppImage"])];
+        assert!(pick_update(&releases, (0, 4, 12), LINUX_EXTENSIONS, false).is_none());
+    }
+}
+
 /// Check whether a newer container image is available in the registry.
 ///
 /// Compares the local image digest with the remote registry digest using the

app/src-tauri/src/docker/container.rs

@@ -1935,7 +1935,7 @@ pub async fn remove_container(container_id: &str) -> Result<(), String> {
         "Removing container {} (v=false: named volumes such as claude config are preserved)",
         container_id
     );
-    docker
+    match docker
         .remove_container(
             container_id,
             Some(RemoveContainerOptions {
@@ -1945,7 +1945,17 @@ pub async fn remove_container(container_id: &str) -> Result<(), String> {
             }),
         )
         .await
-        .map_err(|e| format!("Failed to remove container: {}", e))
+    {
+        Ok(()) => Ok(()),
+        // Already gone is the outcome this call wants, not a failure — a
+        // caller retrying a leftover from a previous, partially-failed removal
+        // (see `remove_project`) must not be told it failed forever just
+        // because a *different* attempt already succeeded.
+        Err(bollard::errors::Error::DockerResponseServerError {
+            status_code: 404, ..
+        }) => Ok(()),
+        Err(e) => Err(format!("Failed to remove container: {}", e)),
+    }
 }
 
 /// Return the snapshot image name for a project.
@@ -3496,13 +3506,27 @@ async fn rewrite_image_without_secrets(
 }
 
 /// Remove the snapshot image for a project (used on Reset / project removal).
+///
+/// A project that never started never built a snapshot, so "no such image" is
+/// the ordinary case, not a failure — it is treated the same as success and
+/// logged at most at `info`. A real failure (the image is in use, a
+/// permission error, the daemon dropped the connection) is the one thing this
+/// returns `Err` for, and callers must not throw that away: see the
+/// `remove_project` doc comment on `ProjectRemovalReport` for why an
+/// unreported failure here used to make the resource unreachable forever.
 pub async fn remove_snapshot_image(project: &Project) -> Result<(), String> {
-    let docker = get_docker()?;
-    let image_name = get_snapshot_image_name(project);
+    remove_image_by_name(&get_snapshot_image_name(project)).await
+}
 
-    docker
+/// Remove a Docker image by name/tag, treating "does not exist" as success.
+/// Shared by [`remove_snapshot_image`] and the pending-cleanup retry, which
+/// only has the image name (the project record is already gone by then).
+pub async fn remove_image_by_name(image_name: &str) -> Result<(), String> {
+    let docker = get_docker()?;
+
+    match docker
         .remove_image(
-            &image_name,
+            image_name,
             Some(RemoveImageOptions {
                 force: true,
                 noprune: false,
@@ -3510,25 +3534,91 @@ pub async fn remove_snapshot_image(project: &Project) -> Result<(), String> {
             None,
         )
         .await
-        .map_err(|e| format!("Failed to remove snapshot image {}: {}", image_name, e))?;
-
+    {
+        Ok(_) => {
             log::info!("Removed snapshot image {}", image_name);
             Ok(())
+        }
+        Err(bollard::errors::Error::DockerResponseServerError {
+            status_code: 404, ..
+        }) => Ok(()),
+        Err(e) => Err(format!("Failed to remove snapshot image {}: {}", image_name, e)),
+    }
 }
 
 /// Remove both named volumes for a project (used on Reset / project removal).
-pub async fn remove_project_volumes(project: &Project) -> Result<(), String> {
-    let docker = get_docker()?;
-    for vol in [
+///
+/// Returns the names of volumes that still exist afterwards — empty means
+/// both are gone (removed here, or never created). This used to always
+/// return `Ok(())` regardless of what actually happened, which made the
+/// `if let Err(e)` at every call site unreachable by construction; see
+/// triple-c#31. A volume Docker reports as simply not existing is not a
+/// leftover and is not included.
+pub async fn remove_project_volumes(project: &Project) -> Vec<String> {
+    remove_volumes_by_name(&[
         home_volume_name(&project.id),
         config_volume_name(&project.id),
-    ] {
-        match docker.remove_volume(&vol, None).await {
+    ])
+    .await
+}
+
+/// Remove a set of named volumes, treating "does not exist" as success.
+/// Returns the names that still exist afterwards — empty means every one is
+/// gone (removed here, or never created).
+///
+/// Shared by [`remove_project_volumes`] and the pending-cleanup retry, the
+/// latter calling this with whatever the former could not remove the first
+/// time. Used to always report success regardless of what actually happened,
+/// which made every `if let Err(e)` at its call sites unreachable by
+/// construction; see triple-c#31.
+pub async fn remove_volumes_by_name(names: &[String]) -> Vec<String> {
+    let docker = match get_docker() {
+        Ok(d) => d,
+        Err(e) => {
+            // Can't reach the daemon to even try, so nothing here can be
+            // confirmed removed. Reporting all as leftover is the safe
+            // direction: worst case a later retry finds them already gone.
+            log::warn!("Could not remove volumes {:?}: {}", names, e);
+            return names.to_vec();
+        }
+    };
+
+    let mut leftover = Vec::new();
+    for vol in names {
+        match remove_one_volume_with_retry(&docker, vol).await {
             Ok(_) => log::info!("Removed volume {}", vol),
-            Err(e) => log::warn!("Failed to remove volume {} (may not exist): {}", vol, e),
+            Err(bollard::errors::Error::DockerResponseServerError {
+                status_code: 404, ..
+            }) => {}
+            Err(e) => {
+                log::warn!("Failed to remove volume {}: {}", vol, e);
+                leftover.push(vol.clone());
             }
         }
-    Ok(())
+    }
+    leftover
+}
+
+/// Remove one volume, retrying once after a short delay on a 409 ("volume is
+/// in use"). Docker releasing a volume's mount reference after the container
+/// using it is removed is not always instantaneous, so the very first call
+/// site of this — `remove_project`, whose container removal lands
+/// immediately before its volume removal — could otherwise turn an ordinary
+/// race into a permanent pending-cleanup record and an alarming toast for
+/// something that would have cleared itself half a second later.
+async fn remove_one_volume_with_retry(
+    docker: &bollard::Docker,
+    name: &str,
+) -> Result<(), bollard::errors::Error> {
+    match docker.remove_volume(name, None).await {
+        Err(bollard::errors::Error::DockerResponseServerError {
+            status_code: 409, ..
+        }) => {
+            tokio::time::sleep(std::time::Duration::from_millis(500)).await;
+            docker.remove_volume(name, None).await
+        }
+        other => other,
+    }
 }
 
 /// Check whether the existing container's configuration still matches the
@@ -4177,7 +4267,12 @@ mod tests {
         // It goes into `triple-c.custom-env-fingerprint`, which `docker inspect`
         // hands to anything on the host, `docker commit` copies onto the
         // project's snapshot image, and the recreation check logs on a mismatch.
-        let secret = "33da01c1b320644920c20d6b5e0a1c6b3c3451c2";
+        // **Never a real credential.** This literal was the maintainer's actual
+        // Gitea token for fourteen days and ninety-two commits, on a public
+        // mirror — in a test whose whole subject is that secrets do not escape.
+        // A fixture only has to be *a value*; it never has to be a live one, so
+        // there is no version of this that justifies pasting something real.
+        let secret = "not-a-real-token-0000000000000000000000";
         let fp = compute_env_fingerprint(&[EnvVar {
             key: "TEA_TOKEN".to_string(),
             value: secret.to_string(),

app/src-tauri/src/docker/exec.rs

@@ -330,29 +330,58 @@ impl ExecSessionManager {
 /// meant a moment earlier.
 pub const MAX_DROP_BYTES: u64 = 256 * 1024 * 1024;
 
-/// Upload a host file into the container's `/tmp` under `dest_name`. The file is
+/// Upload a host file into `dest_dir` under `dest_name`. The file is
 /// read and packed into the tar inside a blocking task, so the synchronous IO
 /// runs off the async worker. The tar's declared entry size is taken from the
 /// bytes actually read (not a separate `stat`), so a file changing size between
 /// a size check and the read can't desync the header and corrupt the archive.
-/// Returns the in-container path (`/tmp/<dest_name>`).
+/// Returns the in-container path (`<dest_dir>/<dest_name>`).
+///
+/// `dest_dir` must already exist and must already have been checked by the
+/// caller — Docker's archive extractor writes wherever it is pointed. The two
+/// callers both do that first, by different routes because they are answering
+/// different questions: the terminal drop stages into a fixed `/tmp` path it
+/// creates itself, and the Files pane passes the directory the user is looking
+/// at, which `file_commands::resolve_container_dir` has already confirmed
+/// resolves inside `CONTAINER_WRITE_ROOTS`.
 pub async fn upload_host_file_to_container(
     container_id: &str,
     host_path: &str,
+    dest_dir: &str,
     dest_name: &str,
+) -> Result<String, String> {
+    let ids = container_user_ids(container_id).await;
+    upload_host_file_with_ids(container_id, host_path, dest_dir, dest_name, ids).await
+}
+
+/// [`upload_host_file_to_container`] for a caller that already knows the
+/// container user's ids.
+///
+/// `container_user_ids` is a `docker exec`, and the Files pane's upload is a
+/// *selection* — one dialog can hand back twenty files. Resolving the ids per
+/// file made twenty extra round trips to answer the same `id -u` twenty times,
+/// which is seconds of latency for a fact that cannot change inside one
+/// container's lifetime. So the loop resolves once and passes the answer in.
+/// The wrapper above keeps the single-file callers unchanged.
+pub async fn upload_host_file_with_ids(
+    container_id: &str,
+    host_path: &str,
+    dest_dir: &str,
+    dest_name: &str,
+    (uid, gid): (u64, u64),
 ) -> Result<String, String> {
     let host_path = host_path.to_string();
     let dest_name = dest_name.to_string();
     let dest_for_blk = dest_name.clone();
-    let (uid, gid) = container_user_ids(container_id).await;
     let mtime = now_epoch_secs();
 
     let tar_buf = tokio::task::spawn_blocking(move || -> Result<Vec<u8>, String> {
         // The caller resolved this path (`resolve_host_read_path`); opening it
         // is a second trip through the same directories, so the descriptor is
         // checked against the path that was validated before its bytes are
-        // packed into anything. This is the terminal's drop target, and it is
-        // the only path by which host bytes enter a container.
+        // packed into anything. Two paths reach here: the terminal's drop
+        // target, and the Files pane's upload via `upload_host_file_with_ids`.
+        // Between them they are how host bytes enter a container.
         let file = std::fs::File::open(&host_path)
             .map_err(|e| format!("Failed to read {}: {}", host_path, e))?;
         crate::commands::file_commands::verify_opened_path(
@@ -381,7 +410,7 @@ pub async fn upload_host_file_to_container(
         .upload_to_container(
             container_id,
             Some(UploadToContainerOptions {
-                path: "/tmp".to_string(),
+                path: dest_dir.to_string(),
                 ..Default::default()
             }),
             tar_buf.into(),
@@ -389,7 +418,17 @@ pub async fn upload_host_file_to_container(
         .await
         .map_err(|e| format!("Failed to upload file to container: {}", e))?;
 
-    Ok(format!("/tmp/{}", dest_name))
+    Ok(container_join(dest_dir, &dest_name))
+}
+
+/// Join a container directory to a name that may itself carry separators.
+///
+/// Only the *reported* path — the bytes have already landed by the time this is
+/// called — but that path is what the terminal echoes and what the Files pane
+/// puts in its toast, so `/tmp//x` reading back as a different file than `/tmp/x`
+/// is worth the four lines. `"/"` trims to `""` and yields `/x`.
+fn container_join(dir: &str, name: &str) -> String {
+    format!("{}/{}", dir.trim_end_matches('/'), name.trim_start_matches('/'))
 }
 
 /// Write `data` into the container at `<dest_dir>/<file_name>` with `mode`.
@@ -779,8 +818,17 @@ pub async fn wait_for_exec_exit(exec_id: &str) -> Option<i64> {
         match docker.inspect_exec(exec_id).await {
             Ok(info) => {
                 if info.running != Some(true) {
-                    // Finished: use the reported code (default 0 if somehow absent).
-                    return Some(info.exit_code.unwrap_or(0));
+                    // Finished. `exit_code` rather than `unwrap_or(0)`: an exec
+                    // that has stopped without a reported code is a status
+                    // nobody can vouch for, and flattening it to *success* is
+                    // the wrong default when a caller is deciding whether to
+                    // rename a downloaded file over the user's own.
+                    // `download_container_file` treats `None` as a failure
+                    // precisely because it cannot tell that silence from a
+                    // clean exit; an `unwrap_or` here made that check
+                    // unreachable. Callers that only care about "did it fail
+                    // loudly" use `is_some_and`, which reads `None` as before.
+                    return info.exit_code;
                 }
             }
             Err(_) => return None,
@@ -892,4 +940,25 @@ mod tests {
         // …but still comfortably above a genuine /proc/net/tcp{,6} pair.
         assert!(PROC_NET_OUTPUT_LIMIT > 100 * 150);
     }
+
+    /// The reported path, which is what the terminal echoes back to Claude and
+    /// what the Files pane puts in its log line. `/tmp//x` and `/tmp/x` are the
+    /// same file to the kernel and different strings to a person reading either
+    /// of those.
+    #[test]
+    fn container_join_produces_one_separator() {
+        assert_eq!(container_join("/tmp", "a.txt"), "/tmp/a.txt");
+        // The terminal's drop passes a nested name; it must not gain a second
+        // slash at the seam.
+        assert_eq!(
+            container_join("/tmp", "triple-c-drops/a.txt"),
+            "/tmp/triple-c-drops/a.txt"
+        );
+        // A directory the user navigated to can carry a trailing slash, and the
+        // container root is the case where trimming it must not eat the only
+        // separator there is.
+        assert_eq!(container_join("/workspace/", "a.txt"), "/workspace/a.txt");
+        assert_eq!(container_join("/", "a.txt"), "/a.txt");
+        assert_eq!(container_join("/", "/a.txt"), "/a.txt");
+    }
 }

app/src-tauri/src/lib.rs

@@ -29,6 +29,21 @@ pub struct AppState {
     pub auth_bridge: Arc<AuthBridgeManager>,
     pub web_terminal_server: Arc<tokio::sync::Mutex<Option<WebTerminalServer>>>,
     pub lifecycle: Arc<Lifecycle>,
+    /// The file `preview_settings_import` last decrypted successfully, held
+    /// so `apply_settings_import` can re-read and re-decrypt the same file
+    /// without the frontend ever passing a host path back to Rust as an
+    /// argument — see the doc comment on `commands::settings_export_commands`
+    /// for why that direction specifically is the one this app treats as
+    /// dangerous. Deliberately re-decrypted rather than cached in plaintext:
+    /// nothing here holds a decrypted secret in memory for longer than one
+    /// command's execution.
+    ///
+    /// Also pins a hash of the file's ciphertext at preview time, so
+    /// `apply_settings_import` can refuse to proceed if the file on disk
+    /// changed underneath the pending import — otherwise confirming a
+    /// preview is not actually binding on what gets applied.
+    pub pending_settings_import:
+        Arc<tokio::sync::Mutex<Option<commands::settings_export_commands::PendingSettingsImport>>>,
 }
 
 // ─────────────────────────────────────────────────────────────────────────────
@@ -222,6 +237,7 @@ pub fn run() {
             auth_bridge,
             web_terminal_server: Arc::new(tokio::sync::Mutex::new(None)),
             lifecycle,
+            pending_settings_import: Arc::new(tokio::sync::Mutex::new(None)),
         })
         .setup(move |app| {
             match tauri::image::Image::from_bytes(include_bytes!("../icons/icon.png")) {
@@ -250,6 +266,7 @@ pub fn run() {
             // an image open and the sweep will not force; pins are untagged
             // second so the images they were holding are dangling by the time
             // the sweep lists them; the sweep runs last and collects both.
+            let projects_store_for_cleanup = projects_store_setup.clone();
             tauri::async_runtime::spawn(async move {
                 crate::docker::reap_probe_containers().await;
                 let reaped = crate::docker::reap_stale_migration_pins().await;
@@ -257,6 +274,15 @@ pub fn run() {
                     log::info!("Startup housekeeping dropped {} stale rollback pin(s)", reaped);
                 }
                 crate::docker::sweep_orphaned_snapshots_logged("startup").await;
+                // A container/image/volume `remove_project` could not delete
+                // is recorded rather than lost — see triple-c#31 — and this is
+                // the only place anything ever retries it. Takes the store so
+                // it can refuse to touch a project that turns out to still be
+                // live — see the long comment on the function itself.
+                crate::commands::project_commands::retry_pending_cleanup_logged(
+                    &projects_store_for_cleanup,
+                )
+                .await;
             });
 
             // Auto-start web terminal server if enabled in settings
@@ -484,6 +510,10 @@ pub fn run() {
             commands::settings_commands::inspect_ca_cert_path,
             commands::settings_commands::list_aws_profiles,
             commands::settings_commands::detect_host_timezone,
+            // Settings export/import
+            commands::settings_export_commands::export_settings,
+            commands::settings_export_commands::preview_settings_import,
+            commands::settings_export_commands::apply_settings_import,
             // Terminal
             commands::terminal_commands::open_terminal_session,
             commands::terminal_commands::terminal_input,
@@ -497,6 +527,8 @@ pub fn run() {
             // Files
             commands::file_commands::list_container_files,
             commands::file_commands::download_container_backup,
+            commands::file_commands::download_container_file,
+            commands::file_commands::upload_files_to_container,
             commands::file_commands::read_container_file,
             commands::file_commands::rename_container_path,
             commands::file_commands::create_container_directory,

app/src-tauri/src/main.rs

@@ -1,6 +1,136 @@
 // Prevents additional console window on Windows in release
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
 
+/// WebKitGTK's DMA-BUF renderer (its default accelerated-compositing path
+/// since 2.42) fails outright on some Mesa/driver/compositor combinations
+/// under Wayland, printing `Could not create default EGL display:
+/// EGL_BAD_PARAMETER. Aborting.` straight to stderr from WebKitGTK's own C
+/// code and killing the webview before Triple-C's own logging even starts —
+/// see triple-c#34, reported on CachyOS/Arch with Wayland.
+///
+/// Set unconditionally on Linux rather than gated on `WAYLAND_DISPLAY`: that
+/// variable is exported into an XWayland client's environment too, so a
+/// gate on it wouldn't even cleanly separate "Wayland" from "X11" — and
+/// there is no reliable heuristic at all for the actual variable that
+/// matters, which Mesa/driver/compositor combination is affected. This is
+/// the blunt instrument, chosen deliberately because the fallback is a real
+/// trade, not a free one: the terminal's `@xterm/addon-webgl` renderer
+/// (`TerminalView.tsx`) is the one surface in this app actually asking for
+/// GPU compositing, and it degrades to xterm's canvas renderer under this
+/// setting — slower on very heavy output, but the addon's own construction
+/// is already wrapped in a fallback (`WebGL not available` is a handled
+/// case, not a crash), so this is a real but graceful downgrade, traded
+/// against a startup abort that has no fallback at all.
+///
+/// Must be set before `triple_c_lib::run()` — GTK/WebKitGTK reads it at
+/// their own init time, which happens inside the Tauri builder that
+/// function calls into, not at binary load.
+///
+/// A user who has already set this themselves is left alone — with one
+/// correction. The earlier version of this function left *any* pre-set value
+/// alone, including `0`, on the assumption WebKitGTK reads the variable as a
+/// boolean. WebKitGTK reads it as presence-only, so `WEBKIT_DISABLE_DMABUF_
+/// RENDERER=0` disabled DMA-BUF exactly like `=1` did, and there was no value
+/// at all a user could set to get the accelerated path back: the escape hatch
+/// the comment described did not exist. `0`, `false` and empty are now treated
+/// as an explicit opt-out and the variable is *removed*, which is the only
+/// thing WebKitGTK reads as "enabled". The default is unchanged — unset still
+/// means disabled on Linux, so nobody who was not deliberately overriding this
+/// sees any difference.
+///
+/// That matters more than it looks, because the trade described above is not
+/// the trade actually being made. `@xterm/addon-webgl` does not fall back to
+/// the canvas renderer here: its constructor throws only when WebGL is
+/// *absent*, and with DMA-BUF disabled WebGL is still present — served by
+/// software rasterisation. So the addon loads happily and every terminal frame
+/// is rendered on the CPU and copied, which is slower than the canvas renderer
+/// this comment assumed it would degrade to, not faster. See
+/// `terminal_gpu_rendering` in `AppSettings` for the switch that decides
+/// whether the addon is loaded at all.
+///
+/// This env var also leaks to whatever the app spawns afterwards — notably
+/// a cold-launched default browser via the `opener` plugin's `xdg-open`
+/// call. Narrow in practice (an already-running browser just receives the
+/// URL; most non-WebKitGTK browsers ignore the variable entirely), but
+/// worth knowing before chasing the "links don't open" half of triple-c#34
+/// as a separate, unrelated cause.
+#[cfg(target_os = "linux")]
+const DMABUF_VAR: &str = "WEBKIT_DISABLE_DMABUF_RENDERER";
+
+/// What to do with `WEBKIT_DISABLE_DMABUF_RENDERER`, given whatever it is
+/// already set to. Split from the mutation so it can be tested without
+/// touching process-wide environment state from a parallel test runner.
+#[cfg(target_os = "linux")]
+#[derive(Debug, PartialEq, Eq)]
+enum DmabufAction {
+    /// Not set by the user — apply the workaround.
+    Disable,
+    /// Explicitly opted out. WebKitGTK reads presence, not value, so the only
+    /// way to express "enabled" is for the variable not to exist.
+    Remove,
+    /// Set to something meaning "disabled". Already what we want; leave it.
+    LeaveAlone,
+}
+
+#[cfg(target_os = "linux")]
+fn dmabuf_action(current: Option<&str>) -> DmabufAction {
+    match current {
+        None => DmabufAction::Disable,
+        Some(value) => match value.trim().to_ascii_lowercase().as_str() {
+            "" | "0" | "false" | "no" => DmabufAction::Remove,
+            _ => DmabufAction::LeaveAlone,
+        },
+    }
+}
+
+#[cfg(target_os = "linux")]
+fn apply_webkit_wayland_workaround() {
+    let current = std::env::var(DMABUF_VAR).ok();
+    match dmabuf_action(current.as_deref()) {
+        DmabufAction::Disable => std::env::set_var(DMABUF_VAR, "1"),
+        DmabufAction::Remove => std::env::remove_var(DMABUF_VAR),
+        DmabufAction::LeaveAlone => {}
+    }
+}
+
+#[cfg(all(test, target_os = "linux"))]
+mod tests {
+    use super::{dmabuf_action, DmabufAction};
+
+    #[test]
+    fn unset_gets_the_workaround() {
+        assert_eq!(dmabuf_action(None), DmabufAction::Disable);
+    }
+
+    #[test]
+    fn falsey_values_opt_out_by_removing_the_variable() {
+        // The bug this replaces: these all previously read as "user set it,
+        // leave it alone", and WebKitGTK then disabled DMA-BUF anyway because
+        // it only checks presence. There was no way to ask for the GPU path.
+        for value in ["0", "false", "no", "", "  0  ", "FALSE", "No"] {
+            assert_eq!(
+                dmabuf_action(Some(value)),
+                DmabufAction::Remove,
+                "{value:?} should opt out"
+            );
+        }
+    }
+
+    #[test]
+    fn other_values_are_left_alone() {
+        for value in ["1", "true", "yes", "anything"] {
+            assert_eq!(
+                dmabuf_action(Some(value)),
+                DmabufAction::LeaveAlone,
+                "{value:?} should be left alone"
+            );
+        }
+    }
+}
+
 fn main() {
+    #[cfg(target_os = "linux")]
+    apply_webkit_wayland_workaround();
+
     triple_c_lib::run()
 }

app/src-tauri/src/models/app_settings.rs

@@ -135,6 +135,26 @@ pub struct AppSettings {
     pub gateway: GatewaySettings,
     #[serde(default)]
     pub global_claude_code_settings: Option<ClaudeCodeSettings>,
+    /// Whether the terminal loads `@xterm/addon-webgl`.
+    ///
+    /// `None` is "auto", and auto is not the same answer on every platform.
+    /// On Linux the app disables WebKitGTK's DMA-BUF renderer at startup (see
+    /// `apply_webkit_wayland_workaround` in `main.rs`, and triple-c#34), which
+    /// does not remove WebGL — it leaves it backed by software rasterisation.
+    /// The addon therefore loads successfully and then renders every frame on
+    /// the CPU, which is slower than the canvas renderer it would otherwise
+    /// have fallen back to. So auto means enabled on macOS and Windows, and
+    /// disabled on Linux.
+    ///
+    /// `Some(true)` / `Some(false)` force it either way on any platform. A
+    /// Linux user running X11, or one whose driver stack is unaffected, can
+    /// turn it back on; anyone seeing terminal lag can turn it off without
+    /// waiting for a release. Deliberately `Option<bool>` rather than `bool`:
+    /// the zero value has to mean "we choose", not "off", or every existing
+    /// settings file would silently pin the answer at whatever the default was
+    /// the day it was written.
+    #[serde(default)]
+    pub terminal_gpu_rendering: Option<bool>,
 }
 
 fn default_stt_model() -> String {
@@ -226,6 +246,7 @@ impl Default for AppSettings {
             stt: SttSettings::default(),
             gateway: GatewaySettings::default(),
             global_claude_code_settings: None,
+            terminal_gpu_rendering: None,
         }
     }
 }

app/src-tauri/src/models/mod.rs

@@ -3,6 +3,7 @@ pub mod container_config;
 pub mod app_settings;
 pub mod gateway_settings;
 pub mod migration;
+pub mod settings_export;
 pub mod update_info;
 
 pub use project::*;
@@ -10,4 +11,5 @@ pub use container_config::*;
 pub use app_settings::*;
 pub use gateway_settings::*;
 pub use migration::*;
+pub use settings_export::*;
 pub use update_info::*;

app/src-tauri/src/models/project.rs

@@ -422,6 +422,61 @@ pub enum ProjectStatus {
     Error,
 }
 
+/// What `remove_project` could not delete, named so the UI can say so instead
+/// of reporting a clean removal that was not one.
+///
+/// The project record is dropped from `projects.json` regardless — see the
+/// long comment on `remove_project` for why refusing is not the answer — but
+/// anything named here is also written to a pending-cleanup record that
+/// startup housekeeping retries, so it stays reachable after the project it
+/// belonged to no longer exists.
+#[derive(Debug, Default, Clone, Serialize, Deserialize)]
+pub struct ProjectRemovalReport {
+    /// The project's container, if it could not be removed. Named by its
+    /// deterministic `triple-c-{id}` name (see `Project::container_name`),
+    /// not the container id, since the id can be stale or absent and the
+    /// name is what a later retry can still resolve.
+    pub container: Option<String>,
+    /// The `triple-c-snapshot-{id}` image, if it could not be removed.
+    pub image: Option<String>,
+    /// Named volumes (home, claude config) that could not be removed.
+    pub volumes: Vec<String>,
+    /// True once the leftovers above were durably recorded for automatic
+    /// retry on the next launch. False means the pending-cleanup record
+    /// itself could not be written — nothing will retry these, and the UI
+    /// must say so rather than promising a retry that will not happen.
+    /// Meaningless (and left at its default) when `is_clean()` is true.
+    pub retry_scheduled: bool,
+}
+
+impl ProjectRemovalReport {
+    /// True when nothing was left behind.
+    pub fn is_clean(&self) -> bool {
+        self.container.is_none() && self.image.is_none() && self.volumes.is_empty()
+    }
+}
+
+/// What `rebuild_project_container` (Reset) produced: the project as it
+/// stands after restarting, and anything Reset could not clear.
+///
+/// Reset's contract is "back to a clean base image", so a leftover volume or
+/// image here is reused/rebuilt-from as-is by the container this creates —
+/// the opposite of what was asked for — and unlike [`ProjectRemovalReport`]
+/// there is no pending-cleanup record for either: the project id survives
+/// Reset, so a later Reset attempt can retry them itself.
+#[derive(Debug, Clone, Serialize)]
+pub struct ProjectResetOutcome {
+    pub project: Project,
+    /// The `triple-c-snapshot-{id}` image, if Reset could not remove it. The
+    /// more serious of the two leftovers here: the new container is created
+    /// from this image whenever it exists, so a surviving image means Reset
+    /// silently rebuilt the exact system layer it was asked to discard.
+    pub leftover_image: Option<String>,
+    /// Volumes that survived Reset and were mounted into the new container
+    /// unchanged.
+    pub leftover_volumes: Vec<String>,
+}
+
 /// Which AI model backend/provider the project uses.
 /// - `Anthropic`: Direct Anthropic API (user runs `claude login` inside the container)
 /// - `Bedrock`: AWS Bedrock with per-project AWS credentials
@@ -650,6 +705,25 @@ impl Project {
 mod tests {
     use super::*;
 
+    // ── ProjectRemovalReport ────────────────────────────────────────────────
+
+    #[test]
+    fn a_report_is_clean_only_with_nothing_left_behind() {
+        assert!(ProjectRemovalReport::default().is_clean());
+
+        let mut r = ProjectRemovalReport::default();
+        r.container = Some("abc123".to_string());
+        assert!(!r.is_clean(), "a leftover container must not read as clean");
+
+        let mut r = ProjectRemovalReport::default();
+        r.image = Some("triple-c-snapshot-x:latest".to_string());
+        assert!(!r.is_clean(), "a leftover image must not read as clean");
+
+        let mut r = ProjectRemovalReport::default();
+        r.volumes.push("triple-c-home-x".to_string());
+        assert!(!r.is_clean(), "a leftover volume must not read as clean");
+    }
+
     // ── Custom environment variable names ─────────────────────────────────
 
     #[test]

app/src-tauri/src/models/settings_export.rs

@@ -0,0 +1,366 @@
+//! Settings export/import — see triple-c#35.
+//!
+//! `SettingsExportPayload` is the whole plaintext export before encryption
+//! and after decryption (see `storage::settings_crypto`). It bundles
+//! `AppSettings` — with one field carved out, see below — with the global
+//! secrets that live in the OS keychain instead: the shared Claude Code
+//! OAuth login and the model gateway's two keys. Per-project settings,
+//! per-project secrets, and anything living in a project's Docker volumes
+//! are deliberately out of scope: this exports the *host* environment, not
+//! any one project's.
+//!
+//! **`AppSettings` is not entirely the non-secret shape it looks like.**
+//! `WebTerminalSettings::access_token` is a live bearer credential for a
+//! server that binds every interface, stored as a plain field on the
+//! struct that is otherwise safe to treat as config. A review of this
+//! feature caught it: exporting `AppSettings` wholesale would have carried
+//! that token along as if it were as inert as a port number, and — worse —
+//! importing it would apply `web_terminal.enabled` and the token together
+//! with no more warning than any other setting, letting a crafted export
+//! silently stand up a LAN-listening terminal server with an
+//! attacker-known token on the next launch. `export_settings` /
+//! `apply_settings_import` blank this field out of the `settings` they
+//! read from and write to, and it travels only through
+//! [`ExportedSecrets::web_terminal_access_token`] instead, with the same
+//! "only overwrite what the import actually has" treatment as the other
+//! three secrets.
+
+use serde::{Deserialize, Serialize};
+
+use super::{AppSettings, ImageSource};
+
+/// Bumped when the shape of [`SettingsExportPayload`] changes in a way that
+/// isn't just an additive, `#[serde(default)]`-covered field — e.g. if a
+/// field is ever removed or its meaning changes. `apply_settings_import`
+/// checks this before touching anything.
+pub const SETTINGS_EXPORT_FORMAT_VERSION: u32 = 1;
+
+/// The global secrets bundled into an export. Deliberately a separate struct
+/// from `AppSettings`: these live in the OS keychain, never in
+/// `settings.json`, and — outside of this export/import flow — the values
+/// themselves never cross into the frontend; see the doc comments on
+/// `storage::secure::get_gateway_api_key` and
+/// `commands::settings_export_commands` for why that boundary matters here
+/// too.
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct ExportedSecrets {
+    #[serde(default)]
+    pub claude_oauth_token: Option<String>,
+    #[serde(default)]
+    pub gateway_api_key: Option<String>,
+    #[serde(default)]
+    pub gateway_master_key: Option<String>,
+    /// See the module doc comment — this is `AppSettings::web_terminal
+    /// .access_token`, carved out because it is a live bearer credential,
+    /// not config, despite living on a struct that is otherwise safe to
+    /// export wholesale.
+    #[serde(default)]
+    pub web_terminal_access_token: Option<String>,
+}
+
+impl ExportedSecrets {
+    pub fn is_empty(&self) -> bool {
+        let blank = |s: &Option<String>| s.as_deref().is_none_or(|v| v.trim().is_empty());
+        blank(&self.claude_oauth_token)
+            && blank(&self.gateway_api_key)
+            && blank(&self.gateway_master_key)
+            && blank(&self.web_terminal_access_token)
+    }
+}
+
+/// What `apply_settings_import` hands back: the settings that were actually
+/// saved, plus a human-readable note for each keychain secret this import
+/// carried but could not be restored. A keychain write failing partway
+/// through must not read as unqualified success just because the settings
+/// half of the import went through.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SettingsImportOutcome {
+    pub settings: AppSettings,
+    #[serde(default)]
+    pub secret_restore_warnings: Vec<String>,
+}
+
+/// The full plaintext payload — this is what gets encrypted on export and
+/// what decryption recovers on import. Never written to disk unencrypted;
+/// see `storage::settings_crypto`.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SettingsExportPayload {
+    pub format_version: u32,
+    /// RFC3339. Purely informational — shown in the import preview so a user
+    /// picking between a few old export files has something to go on.
+    pub exported_at: String,
+    /// The exporting app's `CARGO_PKG_VERSION`. Also informational: every
+    /// field below already round-trips through `#[serde(default)]`-covered
+    /// `AppSettings`, so an older or newer export still deserializes; this is
+    /// for a human to notice "this is from a much older version" if an import
+    /// ever looks wrong, not something the code branches on.
+    pub app_version: String,
+    pub settings: AppSettings,
+    #[serde(default)]
+    pub secrets: ExportedSecrets,
+}
+
+/// What `preview_settings_import` hands the frontend before anything is
+/// applied — counts and presence flags only, **never** a secret value itself,
+/// so this type is safe to return across the IPC boundary and render
+/// directly. The confirmation UI is built from this.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SettingsImportPreview {
+    pub exported_at: String,
+    pub app_version: String,
+    pub custom_env_var_count: usize,
+    pub gateway_model_count: usize,
+    pub has_claude_code_settings: bool,
+    pub has_claude_oauth_token: bool,
+    pub has_gateway_api_key: bool,
+    pub has_gateway_master_key: bool,
+    pub has_web_terminal_access_token: bool,
+    /// Whether the imported settings turn the web terminal on. Named
+    /// separately from the token above: `enabled` and the token are two
+    /// different fields, either can be true without the other, and
+    /// "this import turns on a service that listens on your network" is
+    /// exactly the kind of change a wholesale settings replace must not
+    /// bury in a generic "settings replaced" line — see the module doc
+    /// comment on why this field exists at all.
+    pub enables_web_terminal: bool,
+    /// Non-blank custom base URLs the import would set, so a redirect of
+    /// model traffic to somewhere other than the usual provider is visible
+    /// at import time rather than discovered later. These are endpoints, not
+    /// secrets — safe to show verbatim, unlike everything above.
+    #[serde(default)]
+    pub ollama_base_url: Option<String>,
+    #[serde(default)]
+    pub llamacpp_base_url: Option<String>,
+    #[serde(default)]
+    pub openai_compatible_base_url: Option<String>,
+    #[serde(default)]
+    pub gateway_api_base: Option<String>,
+    /// Whether the import sets a custom Docker image, and its name if so —
+    /// disclosed for the same reason as the base URLs above, and arguably
+    /// more sharply: this is the image *every* project container is created
+    /// from (`models::container_config::resolve_image_name`), so a crafted
+    /// export pointing it at an attacker-controlled image is a path to
+    /// running arbitrary code with whatever a project's containers are
+    /// allowed to reach (the Docker socket, an SSH key, project files) —
+    /// not merely a redirected API endpoint.
+    #[serde(default)]
+    pub image_source: ImageSource,
+    #[serde(default)]
+    pub custom_image_name: Option<String>,
+}
+
+/// A cap on how much of a decrypted, not-yet-trusted string gets echoed back
+/// into a preview a user reads and a UI renders without truncation of its
+/// own. Applied to every field above that carries free-form text straight
+/// from the import file rather than a count or a boolean — a base URL or an
+/// image name a hostile export author controls has had no validation done
+/// on it yet at preview time, and nothing stops it from being pathological
+/// (embedded control characters, or long enough to blow out the confirmation
+/// dialog and push the security warnings below it off screen).
+const MAX_PREVIEW_STRING_LEN: usize = 100;
+
+fn sanitize_for_preview(value: &str) -> String {
+    let cleaned: String = value.chars().filter(|c| !c.is_control()).collect();
+    let trimmed = cleaned.trim();
+    if trimmed.chars().count() > MAX_PREVIEW_STRING_LEN {
+        let truncated: String = trimmed.chars().take(MAX_PREVIEW_STRING_LEN).collect();
+        format!("{}…", truncated)
+    } else {
+        trimmed.to_string()
+    }
+}
+
+impl SettingsImportPreview {
+    pub fn from_payload(payload: &SettingsExportPayload) -> Self {
+        let non_blank = |s: &Option<String>| s.as_deref().is_some_and(|v| !v.trim().is_empty());
+        let sanitized_non_blank = |s: &Option<String>| {
+            s.as_deref()
+                .map(sanitize_for_preview)
+                .filter(|v| !v.is_empty())
+        };
+        Self {
+            exported_at: payload.exported_at.clone(),
+            app_version: payload.app_version.clone(),
+            custom_env_var_count: payload.settings.global_custom_env_vars.len(),
+            gateway_model_count: payload.settings.gateway.models.len(),
+            has_claude_code_settings: payload.settings.global_claude_code_settings.is_some(),
+            has_claude_oauth_token: non_blank(&payload.secrets.claude_oauth_token),
+            has_gateway_api_key: non_blank(&payload.secrets.gateway_api_key),
+            has_gateway_master_key: non_blank(&payload.secrets.gateway_master_key),
+            has_web_terminal_access_token: non_blank(&payload.secrets.web_terminal_access_token),
+            enables_web_terminal: payload.settings.web_terminal.enabled,
+            ollama_base_url: sanitized_non_blank(&payload.settings.global_ollama.base_url),
+            llamacpp_base_url: sanitized_non_blank(&payload.settings.global_llamacpp.base_url),
+            openai_compatible_base_url: sanitized_non_blank(
+                &payload.settings.global_openai_compatible.base_url,
+            ),
+            gateway_api_base: sanitized_non_blank(&payload.settings.gateway.api_base),
+            image_source: payload.settings.image_source.clone(),
+            custom_image_name: sanitized_non_blank(&payload.settings.custom_image_name),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::models::AppSettings;
+
+    fn payload_with(secrets: ExportedSecrets) -> SettingsExportPayload {
+        let settings = AppSettings {
+            global_custom_env_vars: vec![
+                crate::models::EnvVar {
+                    key: "A".to_string(),
+                    value: "1".to_string(),
+                },
+                crate::models::EnvVar {
+                    key: "B".to_string(),
+                    value: "2".to_string(),
+                },
+            ],
+            ..AppSettings::default()
+        };
+        SettingsExportPayload {
+            format_version: SETTINGS_EXPORT_FORMAT_VERSION,
+            exported_at: "2026-08-27T00:00:00Z".to_string(),
+            app_version: "0.4.14".to_string(),
+            settings,
+            secrets,
+        }
+    }
+
+    #[test]
+    fn the_preview_never_carries_a_secret_value() {
+        let payload = payload_with(ExportedSecrets {
+            claude_oauth_token: Some("sk-super-secret-token".to_string()),
+            gateway_api_key: Some("sk-another-secret".to_string()),
+            gateway_master_key: Some("sk-triple-c-yet-another".to_string()),
+            web_terminal_access_token: Some("wt-super-secret-token".to_string()),
+        });
+        let preview = SettingsImportPreview::from_payload(&payload);
+        let serialized = serde_json::to_string(&preview).unwrap();
+
+        assert!(!serialized.contains("sk-super-secret-token"));
+        assert!(!serialized.contains("sk-another-secret"));
+        assert!(!serialized.contains("sk-triple-c-yet-another"));
+        assert!(!serialized.contains("wt-super-secret-token"));
+        assert!(preview.has_claude_oauth_token);
+        assert!(preview.has_gateway_api_key);
+        assert!(preview.has_gateway_master_key);
+        assert!(preview.has_web_terminal_access_token);
+    }
+
+    #[test]
+    fn a_blank_secret_reads_as_absent_in_the_preview() {
+        // A keychain entry that exists but holds only whitespace must not
+        // read as "present" — same "blank counts as absent" rule the
+        // keychain layer itself applies when storing these.
+        let payload = payload_with(ExportedSecrets {
+            claude_oauth_token: Some("   ".to_string()),
+            gateway_api_key: None,
+            gateway_master_key: None,
+            web_terminal_access_token: Some("   ".to_string()),
+        });
+        let preview = SettingsImportPreview::from_payload(&payload);
+        assert!(!preview.has_claude_oauth_token);
+        assert!(!preview.has_gateway_api_key);
+        assert!(!preview.has_gateway_master_key);
+        assert!(!preview.has_web_terminal_access_token);
+    }
+
+    #[test]
+    fn enabling_the_web_terminal_is_surfaced_regardless_of_whether_a_token_came_with_it() {
+        // `enabled` and the token are independent fields — a crafted export
+        // could set one without the other, and both are worth a user's
+        // attention: this is the field that exists specifically so "this
+        // import turns on a service that listens on your network" cannot
+        // hide inside a generic "settings replaced" summary.
+        let mut payload = payload_with(ExportedSecrets::default());
+        payload.settings.web_terminal.enabled = true;
+        let preview = SettingsImportPreview::from_payload(&payload);
+        assert!(preview.enables_web_terminal);
+        assert!(!preview.has_web_terminal_access_token);
+    }
+
+    #[test]
+    fn custom_base_urls_are_surfaced_but_blank_ones_read_as_absent() {
+        let mut payload = payload_with(ExportedSecrets::default());
+        payload.settings.global_ollama.base_url = Some("http://attacker.example:11434".to_string());
+        payload.settings.global_llamacpp.base_url = Some("   ".to_string());
+        payload.settings.gateway.api_base = Some("https://gateway.example/v1".to_string());
+
+        let preview = SettingsImportPreview::from_payload(&payload);
+        assert_eq!(
+            preview.ollama_base_url.as_deref(),
+            Some("http://attacker.example:11434")
+        );
+        assert_eq!(preview.llamacpp_base_url, None);
+        assert_eq!(preview.openai_compatible_base_url, None);
+        assert_eq!(
+            preview.gateway_api_base.as_deref(),
+            Some("https://gateway.example/v1")
+        );
+    }
+
+    #[test]
+    fn counts_reflect_the_real_settings() {
+        let payload = payload_with(ExportedSecrets::default());
+        let preview = SettingsImportPreview::from_payload(&payload);
+        assert_eq!(preview.custom_env_var_count, 2);
+    }
+
+    #[test]
+    fn an_empty_secrets_bundle_reports_itself_as_empty() {
+        assert!(ExportedSecrets::default().is_empty());
+        assert!(!ExportedSecrets {
+            claude_oauth_token: Some("x".to_string()),
+            ..Default::default()
+        }
+        .is_empty());
+    }
+
+    #[test]
+    fn a_secrets_bundle_holding_only_whitespace_still_reports_itself_as_empty() {
+        // Matches the "blank counts as absent" rule every other consumer of
+        // these fields applies (`has_claude_oauth_token` and friends above) —
+        // a keychain entry that exists but holds only whitespace carries
+        // nothing usable, so the export-time "nothing to export" log line
+        // must still fire for it.
+        assert!(ExportedSecrets {
+            claude_oauth_token: Some("   ".to_string()),
+            ..Default::default()
+        }
+        .is_empty());
+    }
+
+    #[test]
+    fn a_custom_docker_image_is_surfaced() {
+        let mut payload = payload_with(ExportedSecrets::default());
+        payload.settings.image_source = crate::models::ImageSource::Custom;
+        payload.settings.custom_image_name = Some("ghcr.io/attacker/triple-c:latest".to_string());
+
+        let preview = SettingsImportPreview::from_payload(&payload);
+        assert_eq!(preview.image_source, crate::models::ImageSource::Custom);
+        assert_eq!(
+            preview.custom_image_name.as_deref(),
+            Some("ghcr.io/attacker/triple-c:latest")
+        );
+    }
+
+    #[test]
+    fn preview_strings_are_stripped_of_control_characters_and_capped_in_length() {
+        let mut payload = payload_with(ExportedSecrets::default());
+        payload.settings.global_ollama.base_url =
+            Some(format!("http://example.test/{}\u{0007}bell", "x".repeat(200)));
+
+        let preview = SettingsImportPreview::from_payload(&payload);
+        let shown = preview.ollama_base_url.expect("non-blank base url");
+        assert!(!shown.contains('\u{0007}'), "control character leaked into the preview");
+        // +1 for the trailing ellipsis appended when truncated.
+        assert!(
+            shown.chars().count() <= MAX_PREVIEW_STRING_LEN + 1,
+            "preview string was not capped: {} chars",
+            shown.chars().count()
+        );
+    }
+}

app/src-tauri/src/models/update_info.rs

@@ -26,6 +26,24 @@ pub struct GitHubRelease {
     pub body: String,
     pub assets: Vec<GitHubAsset>,
     pub published_at: String,
+    /// Whether GitHub itself has this release marked as a prerelease.
+    /// `#[serde(default)]` rather than required: every response GitHub sends
+    /// carries this, but nothing here should refuse to parse the rest of a
+    /// release over one missing field. Defaults to `false` (offered) rather
+    /// than `true` (excluded) — a missing field only happens if GitHub's API
+    /// shape changes, and "API changed, therefore updates silently stop
+    /// working forever" is the worse failure of the two.
+    ///
+    /// `build-app.yml`'s own mirror never publishes a prerelease, but
+    /// `.gitea/workflows/backfill-releases.yml` forwards every Gitea release
+    /// unfiltered, `prerelease` included. A preview release's `preview-<sha>`
+    /// tag already fails semver parsing on its own, so this field is not what
+    /// stops *that* case — it is what stops the case tag-parsing can't catch:
+    /// a normally-tagged release (`v0.4.13`) that someone marks as a
+    /// prerelease on Gitea (a hotfix candidate, an RC) and a backfill then
+    /// mirrors as-is. Real defence for that case, not a no-op.
+    #[serde(default)]
+    pub prerelease: bool,
 }
 
 /// GitHub API asset response (internal).

app/src-tauri/src/storage/mod.rs

@@ -1,6 +1,8 @@
 pub mod migration_store;
+pub mod pending_cleanup;
 pub mod projects_store;
 pub mod secure;
+pub mod settings_crypto;
 pub mod settings_store;
 
 #[allow(unused_imports)]

app/src-tauri/src/storage/pending_cleanup.rs

@@ -0,0 +1,349 @@
+//! Host-side record of Docker resources `remove_project` could not delete.
+//!
+//! `remove_project` drops a project's id from `projects.json` unconditionally
+//! — see the comment on `ProjectRemovalReport` — so once that happens nothing
+//! in the app can name the leftover container, image or volume again by any
+//! path a user can reach. This is what keeps it reachable anyway: one JSON
+//! file per affected project under `<data_dir>/triple-c/pending-cleanup/`,
+//! written *before* the project record is dropped. Startup housekeeping
+//! retries every record on the next launch (see
+//! `commands::project_commands::retry_pending_cleanup_logged`) and deletes
+//! the ones that fully succeed.
+//!
+//! **This record is written in the same instant its record in `projects.json`
+//! is destroyed, and it is the only remaining handle on the leftover
+//! resource** — which is a stronger claim on durability than an ordinary
+//! write-temp-then-rename gives. `storage::migration_store::save` carries the
+//! same reasoning for the migration state file: `fs::write` returns once the
+//! bytes are in the page cache, and a rename over them is atomic with respect
+//! to other readers, not to power loss. A crash in that window leaves the
+//! rename applied and the data half-written, which [`list`] then treats as
+//! unparseable and skips — reproducing the exact bug this module exists to
+//! close, silently, with only a startup log line as evidence. So `save` here
+//! takes the same `File::create` → `write_all` → `sync_all` → `rename` →
+//! directory-sync shape `migration_store` does.
+
+use std::fs;
+use std::path::{Path, PathBuf};
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct PendingCleanup {
+    pub project_id: String,
+    /// Kept only so a log line or a future UI can name the project without a
+    /// second lookup — the project record itself is already gone by the time
+    /// this is read back.
+    pub project_name: String,
+    /// The project's container, if it could not be removed. Named by its
+    /// deterministic `triple-c-{id}` name rather than the (possibly stale)
+    /// container id Docker handed out — Docker's remove-container API
+    /// accepts either, and the name is the one identifier guaranteed to still
+    /// resolve to the same container by the time a retry runs.
+    pub container_id: Option<String>,
+    pub image: Option<String>,
+    pub volumes: Vec<String>,
+    pub recorded_at: String,
+}
+
+impl PendingCleanup {
+    /// True once nothing named here still needs to be removed.
+    pub fn is_empty(&self) -> bool {
+        self.container_id.is_none() && self.image.is_none() && self.volumes.is_empty()
+    }
+}
+
+/// `<data_dir>/triple-c/pending-cleanup`, created on demand.
+fn dir() -> Result<PathBuf, String> {
+    let dir = dirs::data_dir()
+        .ok_or_else(|| {
+            "Could not determine data directory. Set XDG_DATA_HOME on Linux.".to_string()
+        })?
+        .join("triple-c")
+        .join("pending-cleanup");
+    fs::create_dir_all(&dir)
+        .map_err(|e| format!("Failed to create pending-cleanup directory: {}", e))?;
+    Ok(dir)
+}
+
+/// Project ids are UUIDs, but they arrive over IPC, so refuse to let one steer
+/// the write anywhere but the pending-cleanup directory. Mirrors
+/// `storage::migration_store::sanitize`.
+fn sanitize(project_id: &str) -> String {
+    project_id
+        .chars()
+        .map(|c| if c.is_ascii_alphanumeric() || c == '-' || c == '_' { c } else { '_' })
+        .collect()
+}
+
+/// Write (or overwrite) a project's pending-cleanup record.
+pub fn save(record: &PendingCleanup) -> Result<(), String> {
+    save_in(&dir()?, record)
+}
+
+/// Remove a project's pending-cleanup record. Missing is success — this is
+/// how a fully-succeeded retry (or a record that never existed) is expressed.
+pub fn clear(project_id: &str) -> Result<(), String> {
+    clear_in(&dir()?, project_id)
+}
+
+/// Every pending-cleanup record on disk. An unparseable file is logged and
+/// skipped rather than blocking every other project's retry — the same
+/// "one bad record can't wedge the rest" reasoning as the migration store.
+pub fn list() -> Vec<PendingCleanup> {
+    let Ok(dir) = dir() else { return Vec::new() };
+    list_in(&dir)
+}
+
+fn path_in(dir: &Path, project_id: &str) -> PathBuf {
+    dir.join(format!("{}.json", sanitize(project_id)))
+}
+
+/// Durable write: fsync the file before the rename, and fsync the directory
+/// after it — see the module doc comment for why a plain
+/// write-temp-then-rename is not enough here. Mirrors
+/// `storage::migration_store::save`/`sync_dir`.
+fn save_in(dir: &Path, record: &PendingCleanup) -> Result<(), String> {
+    let path = path_in(dir, &record.project_id);
+    let data = serde_json::to_string_pretty(record)
+        .map_err(|e| format!("Failed to serialize pending cleanup record: {}", e))?;
+    let tmp = path.with_extension("json.tmp");
+
+    {
+        use std::io::Write;
+        let mut file = fs::File::create(&tmp)
+            .map_err(|e| format!("Failed to write pending cleanup record: {}", e))?;
+        file.write_all(data.as_bytes())
+            .map_err(|e| format!("Failed to write pending cleanup record: {}", e))?;
+        file.sync_all()
+            .map_err(|e| format!("Failed to flush pending cleanup record to disk: {}", e))?;
+    }
+
+    fs::rename(&tmp, &path)
+        .map_err(|e| format!("Failed to commit pending cleanup record: {}", e))?;
+    sync_dir(&path);
+    Ok(())
+}
+
+fn clear_in(dir: &Path, project_id: &str) -> Result<(), String> {
+    let path = path_in(dir, project_id);
+    match fs::remove_file(&path) {
+        Ok(()) => Ok(()),
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(()),
+        Err(e) => Err(format!("Failed to remove pending cleanup record: {}", e)),
+    }
+}
+
+fn list_in(dir: &Path) -> Vec<PendingCleanup> {
+    let Ok(entries) = fs::read_dir(dir) else { return Vec::new() };
+
+    entries
+        .flatten()
+        .filter(|e| e.path().extension().is_some_and(|ext| ext == "json"))
+        .filter_map(|e| {
+            let path = e.path();
+            let data = fs::read_to_string(&path).ok()?;
+            match serde_json::from_str::<PendingCleanup>(&data) {
+                Ok(record) => Some(record),
+                Err(err) => {
+                    // Moved aside rather than left in place: a record nothing
+                    // ever repairs would otherwise warn on every single
+                    // startup forever, same as an ordinary `.json` file it
+                    // would keep looking like one to `list_in` on the next
+                    // call too. One aside-copy is enough here — this only
+                    // ever holds names to retry removing, not the class of
+                    // once-in-a-lifetime crash evidence `migration_store`
+                    // keeps multiple timestamped backups of.
+                    let corrupt = path.with_extension("json.corrupt");
+                    let moved = !corrupt.exists() && fs::rename(&path, &corrupt).is_ok();
+                    log::warn!(
+                        "Could not parse pending cleanup record {}: {}{}",
+                        path.display(),
+                        err,
+                        if moved {
+                            format!(" — moved aside to {}", corrupt.display())
+                        } else {
+                            " — leaving it in place".to_string()
+                        }
+                    );
+                    None
+                }
+            }
+        })
+        .collect()
+}
+
+/// fsync the directory holding `path`, so a rename into it survives power
+/// loss. Best effort only on the platforms where it is meaningless: Windows
+/// has no directory handle to sync and errors on the attempt, so failure is
+/// logged rather than propagated — the file's own `sync_all` above is what
+/// carries the data. Mirrors `storage::migration_store::sync_dir`, which is
+/// private to that module, so this is a small deliberate duplicate rather
+/// than a shared dependency between two otherwise-independent stores.
+fn sync_dir(path: &Path) {
+    let Some(dir) = path.parent() else { return };
+    match fs::File::open(dir).and_then(|d| d.sync_all()) {
+        Ok(()) => {}
+        Err(e) => log::debug!(
+            "Could not fsync the pending-cleanup directory {}: {} — the record itself was flushed",
+            dir.display(),
+            e
+        ),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn temp_dir(name: &str) -> PathBuf {
+        let dir = std::env::temp_dir().join(format!(
+            "triple-c-pending-cleanup-{}-{}",
+            name,
+            uuid::Uuid::new_v4().simple()
+        ));
+        fs::create_dir_all(&dir).unwrap();
+        dir
+    }
+
+    fn record(project_id: &str) -> PendingCleanup {
+        PendingCleanup {
+            project_id: project_id.to_string(),
+            project_name: "Some Project".to_string(),
+            container_id: Some("triple-c-abc".to_string()),
+            image: Some("triple-c-snapshot-abc:latest".to_string()),
+            volumes: vec!["triple-c-home-abc".to_string()],
+            recorded_at: "2026-08-25T00:00:00Z".to_string(),
+        }
+    }
+
+    #[test]
+    fn project_ids_cannot_escape_the_pending_cleanup_directory() {
+        assert_eq!(sanitize("../../etc/passwd"), "______etc_passwd");
+        assert_eq!(sanitize("a/b"), "a_b");
+        assert_eq!(
+            sanitize("ab62cd24-51aa-4645-8f5c-17a124062050"),
+            "ab62cd24-51aa-4645-8f5c-17a124062050"
+        );
+    }
+
+    #[test]
+    fn is_empty_reflects_whatever_still_needs_removing() {
+        let mut r = record("p1");
+        assert!(!r.is_empty());
+
+        r.container_id = None;
+        r.image = None;
+        assert!(!r.is_empty(), "a leftover volume alone still counts");
+
+        r.volumes.clear();
+        assert!(r.is_empty());
+    }
+
+    /// Exercises the real `save_in`/`list_in`/`clear_in` — not a
+    /// re-implementation of their bodies — against a temp directory standing
+    /// in for `dir()`.
+    #[test]
+    fn a_saved_record_round_trips_and_clearing_removes_it() {
+        let dir = temp_dir("roundtrip");
+        let rec = record("proj-1");
+
+        save_in(&dir, &rec).expect("save");
+        let found = list_in(&dir);
+        assert_eq!(found.len(), 1);
+        assert_eq!(found[0].project_id, "proj-1");
+        assert_eq!(found[0].volumes, vec!["triple-c-home-abc".to_string()]);
+
+        clear_in(&dir, "proj-1").expect("clear");
+        assert!(list_in(&dir).is_empty());
+
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    /// A second `save` for the same project overwrites rather than appending
+    /// — a retry that narrows the leftovers must not leave the old, wider
+    /// record behind it.
+    #[test]
+    fn saving_the_same_project_twice_overwrites_not_appends() {
+        let dir = temp_dir("overwrite");
+        let mut rec = record("proj-1");
+        save_in(&dir, &rec).expect("save");
+
+        rec.container_id = None;
+        rec.image = None;
+        save_in(&dir, &rec).expect("save again");
+
+        let found = list_in(&dir);
+        assert_eq!(found.len(), 1, "one file per project, not one per save");
+        assert!(found[0].container_id.is_none());
+        assert_eq!(found[0].volumes, vec!["triple-c-home-abc".to_string()]);
+
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    /// A record that fails to parse must not poison the rest of the listing.
+    #[test]
+    fn an_unparseable_record_is_skipped_not_fatal() {
+        let dir = temp_dir("corrupt");
+        fs::write(dir.join("bad.json"), "{ not json").unwrap();
+        save_in(&dir, &record("proj-2")).expect("save");
+
+        let found = list_in(&dir);
+        assert_eq!(found.len(), 1);
+        assert_eq!(found[0].project_id, "proj-2");
+
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    /// A record that fails to parse is moved aside once, rather than left in
+    /// place to be re-warned about — and re-warned about — on every future
+    /// launch forever.
+    #[test]
+    fn an_unparseable_record_is_moved_aside_exactly_once() {
+        let dir = temp_dir("corrupt-aside");
+        let bad = dir.join("bad.json");
+        fs::write(&bad, "{ not json").unwrap();
+
+        list_in(&dir);
+        assert!(!bad.exists(), "the bad file should have been moved aside");
+        let corrupt = dir.join("bad.json.corrupt");
+        assert!(corrupt.exists(), "and the moved copy should be at .json.corrupt");
+
+        // A second pass must not warn about `bad.json` again — it is gone —
+        // and must not choke on `.json.corrupt` already being there.
+        assert!(list_in(&dir).is_empty());
+        assert!(corrupt.exists(), "the aside copy is not itself deleted");
+
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    /// `list_in` must not pick up the `.json.tmp` staging file `save_in`
+    /// leaves behind if a crash lands between the write and the rename — the
+    /// whole point of the temp-then-rename dance is that only the renamed
+    /// file is ever a complete record.
+    #[test]
+    fn a_leftover_tmp_file_is_not_listed() {
+        let dir = temp_dir("tmp-leftover");
+        fs::write(dir.join("proj-3.json.tmp"), "not a complete record").unwrap();
+        assert!(list_in(&dir).is_empty());
+
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    /// Clearing by project id must remove exactly the file that id maps to
+    /// under `sanitize`, and nothing else.
+    #[test]
+    fn clearing_one_project_does_not_touch_another() {
+        let dir = temp_dir("clear-scoped");
+        save_in(&dir, &record("proj-a")).unwrap();
+        save_in(&dir, &record("proj-b")).unwrap();
+
+        clear_in(&dir, "proj-a").unwrap();
+
+        let found = list_in(&dir);
+        assert_eq!(found.len(), 1);
+        assert_eq!(found[0].project_id, "proj-b");
+
+        fs::remove_dir_all(&dir).ok();
+    }
+}

app/src-tauri/src/storage/secure.rs

@@ -321,28 +321,52 @@ pub fn delete_gateway_api_key() -> Result<(), String> {
 /// only enforces auth when a master key is configured, so Triple-C always
 /// configures one.
 pub fn get_or_create_gateway_master_key() -> Result<String, String> {
-    if let Some(existing) = read_entry(GATEWAY_MASTER_KEY_SERVICE, "the gateway master key")? {
-        if !existing.trim().is_empty() {
+    if let Some(existing) = get_gateway_master_key()? {
         return Ok(existing);
     }
-    }
     regenerate_gateway_master_key()
 }
 
+/// Read the gateway master key without minting one if none exists yet.
+/// Distinct from [`get_or_create_gateway_master_key`], which mints as a side
+/// effect the read half of that function must not have — settings export
+/// (triple-c#35) needs "is there one, and if so what is it", not "make sure
+/// one exists".
+pub fn get_gateway_master_key() -> Result<Option<String>, String> {
+    Ok(read_entry(GATEWAY_MASTER_KEY_SERVICE, "the gateway master key")?
+        .filter(|k| !k.trim().is_empty()))
+}
+
 /// Mint a new gateway master key, invalidating the old one. Projects using the
 /// previous value must be updated.
 pub fn regenerate_gateway_master_key() -> Result<String, String> {
     // LiteLLM requires the master key to start with `sk-`.
     let key = format!("sk-triple-c-{}", uuid::Uuid::new_v4().simple());
+    store_gateway_master_key(&key)?;
+    Ok(key)
+}
+
+/// Store an exact given gateway master key, replacing any previous one.
+///
+/// Distinct from [`regenerate_gateway_master_key`], which always mints a
+/// fresh random value: this exists for settings import (triple-c#35), where
+/// restoring the *same* key an export captured is the point — projects on
+/// the destination machine may not exist yet, but a project migrated or
+/// re-added later that still has the old key pasted into its config must
+/// keep working against it. Blank input is rejected rather than silently
+/// stored, matching every other `store_*` function in this module.
+pub fn store_gateway_master_key(key: &str) -> Result<(), String> {
+    if key.trim().is_empty() {
+        return Err("Refusing to store an empty gateway master key.".to_string());
+    }
 
     let entry = keyring::Entry::new(GATEWAY_MASTER_KEY_SERVICE, KEYCHAIN_ACCOUNT)
         .map_err(|e| format!("Keyring error: {}", e))?;
     entry
-        .set_password(&key)
+        .set_password(key.trim())
         .map_err(|e| format!("Failed to store the gateway master key: {}", e))?;
 
-    bump_gateway_secret_version()?;
-    Ok(key)
+    bump_gateway_secret_version()
 }
 
 

app/src-tauri/src/storage/settings_crypto.rs

@@ -0,0 +1,184 @@
+//! Password-based encryption for the settings export/import file — see
+//! triple-c#35.
+//!
+//! The exported payload can carry live credentials (the shared Claude OAuth
+//! token, the gateway provider/master keys — see
+//! `commands::settings_export_commands`), so this is not encryption for its
+//! own sake; a wrong or missing key here is a real credential leak, not a
+//! cosmetic bug. Argon2id derives a 256-bit key from the password (memory-
+//! hard, meaningfully resistant to GPU/ASIC brute-forcing in a way PBKDF2 at
+//! any reasonable iteration count is not), and AES-256-GCM is what actually
+//! encrypts — authenticated, so a wrong password is detected by a failed tag
+//! check rather than producing silent garbage.
+//!
+//! File format: `MAGIC (4 bytes) | salt (16 bytes) | nonce (12 bytes) |
+//! ciphertext+tag`. The salt and nonce are not secret — they are written in
+//! the clear right here, on purpose. The salt's only job is to make two
+//! exports with the same password derive different keys (defeats a
+//! precomputed-table attack against the password alone); the nonce's job is
+//! GCM's requirement that a (key, nonce) pair never repeat. Both hold
+//! because a fresh random value is drawn for each, on every call to
+//! [`encrypt`].
+//!
+//! The whole header (magic + salt + nonce) is passed to AES-GCM as
+//! associated data, not just placed alongside the ciphertext — free to do,
+//! and it makes tampering with any header byte fail the same authentication
+//! check the ciphertext gets, by construction rather than as a side effect
+//! of the salt/nonce also feeding key derivation and the cipher.
+
+use aes_gcm::aead::{Aead, KeyInit, Payload};
+use aes_gcm::{Aes256Gcm, Nonce};
+use argon2::{Algorithm, Argon2, Params, Version};
+use rand::RngCore;
+use zeroize::Zeroizing;
+
+/// Identifies the file as a Triple-C settings export and pins the format —
+/// a change to the salt/nonce lengths or the KDF/cipher choice below needs a
+/// new magic value, not a silent reinterpretation of old bytes.
+const MAGIC: &[u8; 4] = b"TCX1";
+const SALT_LEN: usize = 16;
+const NONCE_LEN: usize = 12;
+const KEY_LEN: usize = 32;
+const HEADER_LEN: usize = MAGIC.len() + SALT_LEN + NONCE_LEN;
+
+/// Argon2id parameters: memory cost in KiB, time cost (iterations),
+/// parallelism. `(19 MiB, 2, 1)` is OWASP's documented minimum recommendation
+/// for Argon2id — deliberately heavier than a login-flow KDF would use, since
+/// this runs once per export/import rather than on every request, so trading
+/// roughly a second of wall time for real brute-force resistance costs
+/// nothing a user would notice.
+fn argon2_params() -> Params {
+    Params::new(19 * 1024, 2, 1, Some(KEY_LEN)).expect("hardcoded Argon2 params are valid")
+}
+
+/// The derived key is wrapped in `Zeroizing` so it is overwritten with zeros
+/// when it drops rather than left in freed memory for whatever reuses that
+/// stack slot next — cheap insurance (`zeroize` is already in the dependency
+/// tree via `aes-gcm`) for material that exists only to decrypt live
+/// credentials.
+fn derive_key(password: &str, salt: &[u8]) -> Result<Zeroizing<[u8; KEY_LEN]>, String> {
+    let argon2 = Argon2::new(Algorithm::Argon2id, Version::V0x13, argon2_params());
+    let mut key = Zeroizing::new([0u8; KEY_LEN]);
+    argon2
+        .hash_password_into(password.as_bytes(), salt, &mut *key)
+        .map_err(|e| format!("Failed to derive encryption key: {}", e))?;
+    Ok(key)
+}
+
+/// Encrypt `plaintext` with a key derived from `password`. Returns the whole
+/// file's bytes (header + ciphertext) — see the module doc for the layout.
+pub fn encrypt(plaintext: &[u8], password: &str) -> Result<Vec<u8>, String> {
+    let mut salt = [0u8; SALT_LEN];
+    rand::rng().fill_bytes(&mut salt);
+    let key = derive_key(password, &salt)?;
+
+    let mut nonce_bytes = [0u8; NONCE_LEN];
+    rand::rng().fill_bytes(&mut nonce_bytes);
+    let nonce = Nonce::from_slice(&nonce_bytes);
+
+    let mut header = Vec::with_capacity(HEADER_LEN);
+    header.extend_from_slice(MAGIC);
+    header.extend_from_slice(&salt);
+    header.extend_from_slice(&nonce_bytes);
+
+    let cipher = Aes256Gcm::new_from_slice(&*key)
+        .map_err(|e| format!("Failed to initialize cipher: {}", e))?;
+    // The header (magic + salt + nonce) is authenticated as associated data
+    // even though none of it is secret: it costs nothing extra here, and it
+    // means tampering with any header byte is caught by the same tag check
+    // that already covers the ciphertext, by construction rather than as a
+    // side effect of the header also feeding key/nonce derivation.
+    let ciphertext = cipher
+        .encrypt(nonce, Payload { msg: plaintext, aad: &header })
+        .map_err(|e| format!("Encryption failed: {}", e))?;
+
+    let mut out = header;
+    out.extend_from_slice(&ciphertext);
+    Ok(out)
+}
+
+/// Decrypt a file produced by [`encrypt`]. The one error this returns for a
+/// wrong password is deliberately generic ("wrong password, or the file is
+/// corrupted") rather than distinguishing the two: GCM's authentication tag
+/// fails to verify for the wrong key on essentially any ciphertext, so there
+/// is no reliable way to tell "wrong password" from "corrupted file" apart,
+/// and guessing would be worse than saying so.
+///
+/// Returns `Zeroizing<Vec<u8>>` rather than a plain `Vec<u8>` — the plaintext
+/// this recovers is the whole settings-plus-secrets payload, so it gets the
+/// same "wipe it when it drops" treatment as the derived key in
+/// [`derive_key`].
+pub fn decrypt(data: &[u8], password: &str) -> Result<Zeroizing<Vec<u8>>, String> {
+    if data.len() < HEADER_LEN {
+        return Err("This does not look like a Triple-C settings export (file too short).".to_string());
+    }
+    if &data[..MAGIC.len()] != MAGIC {
+        return Err("This does not look like a Triple-C settings export (unrecognized file).".to_string());
+    }
+    let header = &data[..HEADER_LEN];
+    let salt = &data[MAGIC.len()..MAGIC.len() + SALT_LEN];
+    let nonce_bytes = &data[MAGIC.len() + SALT_LEN..HEADER_LEN];
+    let ciphertext = &data[HEADER_LEN..];
+
+    let key = derive_key(password, salt)?;
+    let cipher = Aes256Gcm::new_from_slice(&*key)
+        .map_err(|e| format!("Failed to initialize cipher: {}", e))?;
+    let nonce = Nonce::from_slice(nonce_bytes);
+    cipher
+        .decrypt(nonce, Payload { msg: ciphertext, aad: header })
+        .map(Zeroizing::new)
+        .map_err(|_| "Wrong password, or the file is corrupted.".to_string())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn a_round_trip_with_the_right_password_recovers_the_plaintext() {
+        let plaintext = b"{\"settings\": \"whatever\"}";
+        let encrypted = encrypt(plaintext, "correct horse battery staple").unwrap();
+        let decrypted = decrypt(&encrypted, "correct horse battery staple").unwrap();
+        assert_eq!(&*decrypted, plaintext);
+    }
+
+    #[test]
+    fn the_wrong_password_fails_rather_than_returning_garbage() {
+        let encrypted = encrypt(b"secret payload", "correct password").unwrap();
+        let result = decrypt(&encrypted, "wrong password");
+        assert!(result.is_err(), "decrypting with the wrong password must fail, not silently succeed");
+    }
+
+    #[test]
+    fn two_exports_of_the_same_plaintext_and_password_produce_different_files() {
+        // If this ever failed it would mean the salt or nonce stopped being
+        // randomized — either one repeating is a real security regression
+        // (a fixed salt lets an attacker precompute against the password
+        // alone; a repeated (key, nonce) pair breaks GCM's guarantees
+        // outright), not just a cosmetic one.
+        let a = encrypt(b"same plaintext", "same password").unwrap();
+        let b = encrypt(b"same plaintext", "same password").unwrap();
+        assert_ne!(a, b, "two independent exports must not be byte-identical");
+    }
+
+    #[test]
+    fn corrupting_a_single_byte_of_ciphertext_is_detected() {
+        let mut encrypted = encrypt(b"tamper-evident payload", "a password").unwrap();
+        let last = encrypted.len() - 1;
+        encrypted[last] ^= 0xFF;
+        assert!(decrypt(&encrypted, "a password").is_err());
+    }
+
+    #[test]
+    fn a_file_that_is_too_short_is_rejected_cleanly_not_by_panicking() {
+        assert!(decrypt(b"short", "any password").is_err());
+        assert!(decrypt(b"", "any password").is_err());
+    }
+
+    #[test]
+    fn a_file_with_the_wrong_magic_is_rejected() {
+        let mut encrypted = encrypt(b"payload", "password").unwrap();
+        encrypted[0] = b'X';
+        assert!(decrypt(&encrypted, "password").is_err());
+    }
+}

app/src-tauri/src/web_terminal/terminal.html

@@ -757,7 +757,13 @@
         sessionType === 'claude'
       ) {
         sendTerminalInput('\x1b\r');
-        return false; // xterm must not also send a bare CR, which submits
+        // `preventDefault()` is what stops the submit, not the `return false`.
+        // xterm's `_keyDown` returns before setting `_keyDownHandled`, so
+        // `_keyPress` still fires and emits a bare CR for Enter — inserting the
+        // newline and then submitting the prompt anyway. See the same comment
+        // in TerminalView.tsx.
+        e.preventDefault();
+        return false;
       }
       return true;
     });

app/src/components/projects/AddProjectDialog.test.tsx

@@ -0,0 +1,118 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent, waitFor, act } from "@testing-library/react";
+import AddProjectDialog from "./AddProjectDialog";
+
+const add = vi.fn();
+
+vi.mock("../../hooks/useProjects", () => ({
+  useProjects: () => ({ add }),
+}));
+
+vi.mock("@tauri-apps/plugin-dialog", () => ({
+  open: vi.fn(async () => null),
+}));
+
+/** A promise whose resolution this test controls, so `loading` can be held open. */
+function deferred() {
+  let resolve!: (v: unknown) => void;
+  const promise = new Promise((r) => {
+    resolve = r;
+  });
+  return { promise, resolve };
+}
+
+function fillValidForm() {
+  fireEvent.change(screen.getByLabelText("Project name"), {
+    target: { value: "my-project" },
+  });
+  fireEvent.change(screen.getByLabelText("Folder 1 host path"), {
+    target: { value: "/home/user/my-project" },
+  });
+}
+
+function submitButton() {
+  return screen.getByRole("button", { name: /Add Project|Adding/ });
+}
+
+describe("AddProjectDialog", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("adds the project with the name and folder entered", async () => {
+    add.mockResolvedValue({ id: "p1" });
+    const onClose = vi.fn();
+    render(<AddProjectDialog onClose={onClose} />);
+    fillValidForm();
+    fireEvent.click(submitButton());
+    await waitFor(() =>
+      expect(add).toHaveBeenCalledWith("my-project", [
+        { host_path: "/home/user/my-project", mount_name: "my-project" },
+      ]),
+    );
+    await waitFor(() => expect(onClose).toHaveBeenCalled());
+  });
+
+  it("keeps the submit button announced, and explains why, while adding", async () => {
+    const { promise, resolve } = deferred();
+    add.mockReturnValue(promise);
+    render(<AddProjectDialog onClose={vi.fn()} />);
+    fillValidForm();
+    fireEvent.click(submitButton());
+
+    // Native `disabled` would remove the button from the accessibility tree
+    // exactly when it has something to say.
+    await waitFor(() =>
+      expect(submitButton()).toHaveAttribute("aria-disabled", "true"),
+    );
+    expect(submitButton()).not.toBeDisabled();
+    expect(submitButton()).toHaveAccessibleDescription(/being added/i);
+
+    await act(async () => resolve({ id: "p1" }));
+  });
+
+  it("ignores clicks and Enter/Space on the submit button while adding", async () => {
+    const { promise, resolve } = deferred();
+    add.mockReturnValue(promise);
+    render(<AddProjectDialog onClose={vi.fn()} />);
+    fillValidForm();
+    fireEvent.click(submitButton());
+    await waitFor(() =>
+      expect(submitButton()).toHaveAttribute("aria-disabled", "true"),
+    );
+
+    fireEvent.click(submitButton());
+    fireEvent.keyDown(submitButton(), { key: "Enter" });
+    fireEvent.keyDown(submitButton(), { key: " " });
+    expect(add).toHaveBeenCalledTimes(1);
+
+    await act(async () => resolve({ id: "p1" }));
+  });
+
+  it("ignores a form submit raised from elsewhere while adding", async () => {
+    const { promise, resolve } = deferred();
+    add.mockReturnValue(promise);
+    render(<AddProjectDialog onClose={vi.fn()} />);
+    fillValidForm();
+    fireEvent.click(submitButton());
+    await waitFor(() =>
+      expect(submitButton()).toHaveAttribute("aria-disabled", "true"),
+    );
+
+    // Enter in a text field submits a form regardless of the submit button's
+    // state, so the handler has to guard itself too.
+    // Modal portals to document.body, so the form is not under `container`.
+    const form = document.querySelector("form");
+    expect(form).not.toBeNull();
+    fireEvent.submit(form!);
+    expect(add).toHaveBeenCalledTimes(1);
+
+    await act(async () => resolve({ id: "p1" }));
+  });
+
+  it("leaves the submit button plainly available when idle", () => {
+    render(<AddProjectDialog onClose={vi.fn()} />);
+    expect(submitButton()).not.toHaveAttribute("aria-disabled");
+    expect(submitButton()).toHaveAccessibleDescription("");
+  });
+});

app/src/components/projects/AddProjectDialog.tsx

@@ -55,6 +55,10 @@ export default function AddProjectDialog({ onClose }: Props) {
 
   const handleSubmit = async (e?: React.FormEvent) => {
     if (e) e.preventDefault();
+    // The submit button is `aria-disabled` rather than `disabled` while an add
+    // is in flight, and Enter inside a text field submits the form without
+    // touching the button at all. Both routes end here, so the guard does too.
+    if (loading) return;
     if (!name.trim()) {
       setError("Project name is required");
       return;
@@ -97,7 +101,19 @@ export default function AddProjectDialog({ onClose }: Props) {
           <Button size="md" variant="ghost" onClick={onClose}>
             Cancel
           </Button>
-          <Button size="md" variant="primary" type="submit" form={formId} disabled={loading}>
+          <Button
+            size="md"
+            variant="primary"
+            type="submit"
+            form={formId}
+            unavailable={loading}
+            unavailableReason="The project is being added. Wait for it to finish."
+            title={
+              loading
+                ? "The project is being added. Wait for it to finish."
+                : undefined
+            }
+          >
             {loading ? "Adding…" : "Add Project"}
           </Button>
         </>

app/src/components/projects/ProjectRow.test.tsx

@@ -122,14 +122,6 @@ describe("ProjectRow", () => {
   });
 
   it("only allows opening a terminal while the container runs", () => {
-    const { unmount } = render(<ProjectRow project={baseProject} />);
-    expect(
-      screen.getByRole("button", {
-        name: "Open a Claude terminal for Test Project",
-      }),
-    ).toBeDisabled();
-    unmount();
-
     render(<ProjectRow project={{ ...baseProject, status: "running" }} />);
     fireEvent.click(
       screen.getByRole("button", {
@@ -139,6 +131,38 @@ describe("ProjectRow", () => {
     expect(mockOpenClaudeTerminal).toHaveBeenCalled();
   });
 
+  it("keeps the terminal button announced, and explains why, while stopped", () => {
+    render(<ProjectRow project={baseProject} />);
+    const button = screen.getByRole("button", {
+      name: "Open a Claude terminal for Test Project",
+    });
+    // Native `disabled` would drop the button out of the accessibility tree
+    // and out of the tab order, taking the reason with it.
+    expect(button).not.toBeDisabled();
+    expect(button).toHaveAttribute("aria-disabled", "true");
+    expect(button).toHaveAccessibleDescription(/is not running/i);
+  });
+
+  it("ignores clicks and Enter/Space on the terminal button while stopped", () => {
+    render(<ProjectRow project={baseProject} />);
+    const button = screen.getByRole("button", {
+      name: "Open a Claude terminal for Test Project",
+    });
+    fireEvent.click(button);
+    fireEvent.keyDown(button, { key: "Enter" });
+    fireEvent.keyDown(button, { key: " " });
+    expect(mockOpenClaudeTerminal).not.toHaveBeenCalled();
+  });
+
+  it("drops aria-disabled once the container is running", () => {
+    render(<ProjectRow project={{ ...baseProject, status: "running" }} />);
+    const button = screen.getByRole("button", {
+      name: "Open a Claude terminal for Test Project",
+    });
+    expect(button).not.toHaveAttribute("aria-disabled");
+    expect(button).not.toHaveAccessibleDescription(/is not running/i);
+  });
+
   it("shows container progress inline rather than in a blocking modal", () => {
     setStore({ containerProgress: { "test-1": "Pulling image…" } });
     render(<ProjectRow project={{ ...baseProject, status: "starting" }} />);

app/src/components/projects/ProjectRow.tsx

@@ -3,6 +3,7 @@ import type { Project } from "../../lib/types";
 import { useAppState, homeTabKey } from "../../store/appState";
 import { useProjectActions } from "../../hooks/useProjectActions";
 import { ProjectStatusIndicator } from "../ui/StatusIndicator";
+import { useUnavailable } from "../ui/unavailable";
 
 interface Props {
   project: Project;
@@ -31,6 +32,15 @@ export default function ProjectRow({ project }: Props) {
   const isTransitioning =
     project.status === "starting" || project.status === "stopping";
 
+  // A terminal needs a running container. Saying so out loud beats a `disabled`
+  // attribute that hides the button — and the reason — from anyone not using a
+  // mouse and eyes.
+  const terminal = useUnavailable({
+    unavailable: !isRunning,
+    reason: `${project.name} is not running. Start it to open a terminal.`,
+    onClick: () => openClaudeTerminal(),
+  });
+
   return (
     <div
       className={`group relative px-2 py-1.5 rounded-[var(--radius-control)] transition-colors min-w-0 overflow-hidden ${
@@ -113,11 +123,14 @@ export default function ProjectRow({ project }: Props) {
         </button>
         <button
           type="button"
-          disabled={!isRunning}
-          onClick={() => openClaudeTerminal()}
-          title={`Open a Claude terminal for ${project.name}`}
+          {...terminal.controlProps}
+          title={
+            isRunning
+              ? `Open a Claude terminal for ${project.name}`
+              : `${project.name} is not running. Start it to open a terminal.`
+          }
           aria-label={`Open a Claude terminal for ${project.name}`}
-          className="w-6 h-6 flex items-center justify-center rounded-[var(--radius-control)] text-[var(--text-secondary)] hover:text-[var(--text-primary)] hover:bg-[var(--bg-primary)] disabled:text-[var(--text-disabled)] transition-colors"
+          className="w-6 h-6 flex items-center justify-center rounded-[var(--radius-control)] text-[var(--text-secondary)] hover:text-[var(--text-primary)] hover:bg-[var(--bg-primary)] disabled:text-[var(--text-disabled)] aria-disabled:text-[var(--text-disabled)] aria-disabled:hover:text-[var(--text-disabled)] aria-disabled:hover:bg-transparent aria-disabled:cursor-not-allowed transition-colors"
         >
           <svg
             className="w-3.5 h-3.5"
@@ -134,6 +147,7 @@ export default function ProjectRow({ project }: Props) {
             <line x1="13" y1="15" x2="17" y2="15" />
           </svg>
         </button>
+        {terminal.reasonNode}
       </div>
     </div>
   );

app/src/components/projects/home/FileViewerModal.tsx

@@ -144,15 +144,16 @@ export default function FileViewerModal({ projectId, entry, onClose }: Props) {
 
       {preview.kind === "too-large" && (
         <p className="text-[13px] text-[var(--text-secondary)]">
-          This file is {formatBytes(entry.size)} — too large to preview in the app. Open it
-          from a terminal in the container, or take a backup and open it on the host.
+          This file is {formatBytes(entry.size)} — too large to preview in the app. Use
+          “Save to host…” on its row to open it in a program that can, or read it from a
+          terminal in the container.
         </p>
       )}
 
       {preview.kind === "unsupported" && (
         <p className="text-[13px] text-[var(--text-secondary)]">
-          There is no preview for this file type. Open it from a terminal in the container,
-          or take a backup and open it on the host.
+          There is no preview for this file type. Use “Save to host…” on its row to open it
+          in a program that can, or read it from a terminal in the container.
         </p>
       )}
 

app/src/components/projects/home/FilesTab.test.tsx

@@ -1,5 +1,5 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
-import { render, screen, fireEvent, act, waitFor } from "@testing-library/react";
+import { render, screen, fireEvent, act, waitFor, within } from "@testing-library/react";
 import FilesTab from "./FilesTab";
 import type { FileContents, FileEntry, Project } from "../../../lib/types";
 
@@ -7,6 +7,8 @@ const listContainerFiles = vi.fn();
 const renameContainerPath = vi.fn(async () => "");
 const createContainerDirectory = vi.fn(async () => "");
 const readContainerFile = vi.fn();
+const uploadFilesToContainer = vi.fn();
+const downloadContainerFile = vi.fn();
 
 vi.mock("../../../lib/tauri-commands", () => ({
   listContainerFiles: (p: string, path: string) => listContainerFiles(p, path),
@@ -14,6 +16,8 @@ vi.mock("../../../lib/tauri-commands", () => ({
   createContainerDirectory: (p: string, parent: string, n: string) =>
     createContainerDirectory(p, parent, n),
   readContainerFile: (p: string, path: string, max?: number) => readContainerFile(p, path, max),
+  uploadFilesToContainer: (p: string, dir: string) => uploadFilesToContainer(p, dir),
+  downloadContainerFile: (p: string, path: string) => downloadContainerFile(p, path),
 }));
 
 /** Transient failures land in `ToastHost`, not in an inline string. */
@@ -175,9 +179,15 @@ describe("FilesTab viewer", () => {
     });
     expect(await screen.findByText(/too large to preview/)).toBeTruthy();
     expect(screen.queryByAltText("huge.png")).toBeNull();
-    // The way out is named, and it is not a host path this pane could write:
-    // a terminal inside the container, or a backup.
-    expect(screen.getByText(/take a backup/)).toBeTruthy();
+    // A refusal has to name the way out, and the way out is now the button on
+    // the row rather than the `cat`-it-in-a-terminal workaround that existed
+    // because the button did not.
+    // Scoped to the modal: every file row also carries a "Save to host…"
+    // button now, so an unscoped query matches the grid behind the overlay and
+    // would pass with the refusal saying nothing at all.
+    expect(
+      within(screen.getByRole("dialog")).getByText(/Save to host/),
+    ).toBeTruthy();
   });
 
   it("says so in words when only a prefix of a big text file came back", async () => {
@@ -392,3 +402,73 @@ describe("FilesTab grid semantics", () => {
     expect(screen.getByRole("alert").textContent).toContain("Permission denied");
   });
 });
+
+/**
+ * The pane's two host-transfer affordances.
+ *
+ * They are asserted at the *button* level and not only in the hook, because
+ * this is the half that was actually lost: the commands behind them had been
+ * deleted, but so had the controls, and a working command nobody can reach is
+ * the same regression. Neither button names a host path — Rust opens the
+ * dialog — so what a click is required to prove is that the container-side
+ * argument reaching the backend is the one the user is looking at.
+ */
+describe("FilesTab host transfers", () => {
+  beforeEach(() => {
+    uploadFilesToContainer.mockResolvedValue({ uploaded: [], failures: [] });
+    downloadContainerFile.mockResolvedValue(4);
+  });
+
+  it("uploads into the directory currently on screen", async () => {
+    listContainerFiles.mockResolvedValue([entry("src", { is_directory: true })]);
+    await renderTab();
+    await act(async () => {
+      fireEvent.doubleClick(screen.getByText("src"));
+    });
+    uploadFilesToContainer.mockResolvedValueOnce({
+      uploaded: ["/workspace/src/a.txt"],
+      failures: [],
+    });
+    await act(async () => {
+      fireEvent.click(screen.getByRole("button", { name: "Upload…" }));
+    });
+    expect(uploadFilesToContainer).toHaveBeenCalledWith("p1", "/workspace/src");
+  });
+
+  it("offers Save to host on a file and not on a folder", async () => {
+    listContainerFiles.mockResolvedValue([
+      entry("notes.txt"),
+      entry("src", { is_directory: true }),
+    ]);
+    await renderTab();
+    // The accessible name carries the row, per WCAG 2.5.3 — and it is how a
+    // per-row action is told apart from every other row's copy of it.
+    expect(
+      screen.getByRole("button", { name: "Save to host — notes.txt" }),
+    ).toBeTruthy();
+    expect(
+      screen.queryByRole("button", { name: "Save to host — src" }),
+    ).toBeNull();
+    await act(async () => {
+      fireEvent.click(screen.getByRole("button", { name: "Save to host — notes.txt" }));
+    });
+    expect(downloadContainerFile).toHaveBeenCalledWith("p1", "/workspace/notes.txt");
+  });
+
+  it("does not open the file viewer when Save to host is double-clicked", async () => {
+    // Opening a file is a *double*-click on the row, and a double-click on a
+    // button inside that row still bubbles — `onClick`'s `stopPropagation` does
+    // nothing about it. So an impatient double-click on Save used to save the
+    // file and drop the viewer modal over the pane at the same time, on top of
+    // the save dialog the backend had just opened.
+    listContainerFiles.mockResolvedValue([entry("notes.txt")]);
+    readContainerFile.mockResolvedValue(contents("hello"));
+    await renderTab();
+    await act(async () => {
+      fireEvent.doubleClick(
+        screen.getByRole("button", { name: "Save to host — notes.txt" }),
+      );
+    });
+    expect(readContainerFile).not.toHaveBeenCalled();
+  });
+});

app/src/components/projects/home/FilesTab.tsx

@@ -15,13 +15,26 @@ const PARENT_ROW = "..";
 /**
  * The project's file browser.
  *
- * Container-side only: it lists, opens, renames and creates folders inside the
- * container, and it does no host filesystem I/O at all. A file gets *into* a
- * container by being dropped onto the Terminal tab, and a whole tree comes back
- * out through "Back up container" in the project's Workspace settings. Four
- * successive audits found that host paths crossing IPC were where the criticals
- * lived; those two paths are the ones that survived, and this pane is not one
- * of them.
+ * It lists, opens, renames and creates folders inside the container, and it
+ * copies single files across the boundary: "Upload…" in the toolbar, and a
+ * per-row "Save to host…".
+ *
+ * **Neither of those names a host path, and this file must never learn how
+ * to.** Four successive audits found that host paths crossing IPC were where
+ * the criticals lived — a frontend `open()`/`save()` handing Rust a string is
+ * exactly the shape that failed — so the picker is opened by the *backend*
+ * (`pick_files_to_upload` / `pick_save_path` in `commands/file_commands.rs`).
+ * What this file *sends* is a project id and a container path; the host side of
+ * the transfer is chosen by a person in an OS dialog. That is why
+ * `uploadFiles()` takes no argument and `saveToHost()` takes only the entry.
+ * (A failed transfer does report a host path back, in the text of its error —
+ * the inbound direction is the one that is closed, not both.)
+ *
+ * Drag-and-drop is deliberately still absent, in both directions. A file also
+ * gets into a container by being dropped onto the Terminal tab, and a whole
+ * tree comes back out through "Back up container" in the project's ⋯ menu —
+ * which is still the right answer for a directory, since "Save to host…" is one
+ * file at a time and is not offered on folders.
  *
  * Interaction model, chosen to match every desktop file manager rather than
  * the old half-and-half: **single click selects, double click opens**. That
@@ -52,6 +65,10 @@ export default function FilesTab({ project }: Props) {
     refresh,
     renameEntry,
     createFolder,
+    uploadFiles,
+    saveToHost,
+    uploading,
+    savingPaths,
   } = useFileManager(project.id);
 
   const running = project.status === "running";
@@ -305,6 +322,16 @@ export default function FilesTab({ project }: Props) {
         >
           New folder
         </Button>
+        {/* The file picker this opens belongs to Rust, not to the webview — so
+            this file imports no dialog plugin and never composes a host path.
+            `uploadFiles` takes no argument for the same reason. */}
+        <Button
+          onClick={() => void uploadFiles()}
+          disabled={uploading}
+          className="ml-1"
+        >
+          {uploading ? "Uploading…" : "Upload…"}
+        </Button>
         <Button onClick={refresh} disabled={loading} className="ml-1">
           Refresh
         </Button>
@@ -501,6 +528,34 @@ export default function FilesTab({ project }: Props) {
                           >
                             Rename
                           </Button>
+                          {/* Folders have no single-file equivalent — a
+                              recursive download is what "Back up container" is
+                              for, and offering one here would mean rebuilding
+                              the tree-walking this pane deliberately does not
+                              do. */}
+                          {!entry.is_directory && (
+                            <Button
+                              aria-label={`Save to host — ${entry.name}`}
+                              className="ml-1"
+                              // Only this row: a large file can take a while,
+                              // and there is no reason the rest of the pane
+                              // should go dead while it is written.
+                              disabled={savingPaths.has(entry.path)}
+                              onClick={(e) => {
+                                e.stopPropagation();
+                                void saveToHost(entry);
+                              }}
+                              // A double-click is its own event, and
+                              // `onClick`'s `stopPropagation` says nothing
+                              // about it — so an impatient double-click here
+                              // reached the row's `onDoubleClick` and dropped
+                              // the viewer modal over the pane, on top of the
+                              // save dialog the backend had just opened.
+                              onDoubleClick={(e) => e.stopPropagation()}
+                            >
+                              {savingPaths.has(entry.path) ? "Saving…" : "Save to host…"}
+                            </Button>
+                          )}
                         </>
                       )}
                     </td>

app/src/components/projects/home/ProjectHome.tsx

@@ -1,5 +1,6 @@
 import { useEffect, useMemo, useState } from "react";
 import { useShallow } from "zustand/react/shallow";
+import { projectRemovalIsClean } from "../../../lib/types";
 import { useAppState } from "../../../store/appState";
 import { useProjectActions } from "../../../hooks/useProjectActions";
 import { useProjects } from "../../../hooks/useProjects";
@@ -18,6 +19,7 @@ import ConfigTab from "./ConfigTab";
 import FilesTab from "./FilesTab";
 import BrowserTab from "./BrowserTab";
 import { formatUptime } from "./format";
+import { describeLeftovers, leftoverPronoun, leftoverVerb } from "./removalReport";
 
 const TABS = [
   { id: "overview", label: "Overview" },
@@ -282,7 +284,25 @@ export default function ProjectHome({ projectId, active }: Props) {
           onConfirm={async () => {
             setConfirmRemove(false);
             try {
-              await remove(project.id);
+              const report = await remove(project.id);
+              if (!projectRemovalIsClean(report)) {
+                const verb = leftoverVerb(report);
+                if (report.retry_scheduled) {
+                  useAppState.getState().pushToast({
+                    kind: "info",
+                    message: `“${project.name}” was removed, but Triple-C could not confirm all its Docker resources were removed`,
+                    detail: `Triple-C could not confirm ${describeLeftovers(report)} ${verb} removed. It will check again the next time it starts.`,
+                  });
+                } else {
+                  // The pending-cleanup record itself failed to save — no
+                  // retry will happen, so this must not promise one.
+                  useAppState.getState().pushToast({
+                    kind: "error",
+                    message: `“${project.name}” was removed, but Triple-C could not confirm its Docker resources were removed`,
+                    detail: `Triple-C could not confirm ${describeLeftovers(report)} ${verb} removed, and could not record this for a retry. You may need to remove ${leftoverPronoun(report)} manually (\`docker rm\` / \`docker rmi\` / \`docker volume rm\`).`,
+                  });
+                }
+              }
             } catch (e) {
               useAppState.getState().pushToast({
                 kind: "error",

app/src/components/projects/home/removalReport.test.ts

@@ -0,0 +1,51 @@
+import { describe, it, expect } from "vitest";
+import { describeLeftovers, leftoverVerb } from "./removalReport";
+import { projectRemovalIsClean } from "../../../lib/types";
+import type { ProjectRemovalReport } from "../../../lib/types";
+
+function report(overrides: Partial<ProjectRemovalReport> = {}): ProjectRemovalReport {
+  return {
+    container: null,
+    image: null,
+    volumes: [],
+    retry_scheduled: false,
+    ...overrides,
+  };
+}
+
+describe("projectRemovalIsClean", () => {
+  it("is true only when nothing survived", () => {
+    expect(projectRemovalIsClean(report())).toBe(true);
+    expect(projectRemovalIsClean(report({ container: "triple-c-abc" }))).toBe(false);
+    expect(projectRemovalIsClean(report({ image: "triple-c-snapshot-abc:latest" }))).toBe(false);
+    expect(projectRemovalIsClean(report({ volumes: ["triple-c-home-abc"] }))).toBe(false);
+  });
+});
+
+describe("describeLeftovers", () => {
+  it("names each kind of leftover", () => {
+    expect(describeLeftovers(report({ container: "triple-c-abc" }))).toBe("its container");
+    expect(describeLeftovers(report({ image: "x" }))).toBe("its saved image");
+    expect(describeLeftovers(report({ volumes: ["v1"] }))).toBe("a volume");
+    expect(describeLeftovers(report({ volumes: ["v1", "v2"] }))).toBe("2 volumes");
+  });
+
+  it("joins multiple kinds together", () => {
+    expect(
+      describeLeftovers(report({ container: "triple-c-abc", image: "x", volumes: ["v1", "v2"] })),
+    ).toBe("its container, its saved image, 2 volumes");
+  });
+});
+
+describe("leftoverVerb", () => {
+  it("is singular for exactly one leftover of any kind", () => {
+    expect(leftoverVerb(report({ container: "triple-c-abc" }))).toBe("was");
+    expect(leftoverVerb(report({ image: "x" }))).toBe("was");
+    expect(leftoverVerb(report({ volumes: ["v1"] }))).toBe("was");
+  });
+
+  it("is plural once more than one thing survived, including multiple volumes alone", () => {
+    expect(leftoverVerb(report({ container: "triple-c-abc", image: "x" }))).toBe("were");
+    expect(leftoverVerb(report({ volumes: ["v1", "v2"] }))).toBe("were");
+  });
+});

app/src/components/projects/home/removalReport.ts

@@ -0,0 +1,39 @@
+import type { ProjectRemovalReport } from "../../../lib/types";
+
+/**
+ * Names what a `ProjectRemovalReport` says survived, for the leftover toast.
+ *
+ * Worded as "could not confirm" rather than "is still on disk": the same
+ * report shape covers a genuine leftover (a locked volume) and a daemon that
+ * was simply unreachable at the time, in which case nothing was ever created
+ * and there is nothing to find — asserting certainty either way would be
+ * wrong in one of those cases.
+ */
+export function describeLeftovers(report: ProjectRemovalReport): string {
+  const parts: string[] = [];
+  if (report.container) parts.push("its container");
+  if (report.image) parts.push("its saved image");
+  if (report.volumes.length === 1) parts.push("a volume");
+  else if (report.volumes.length > 1) parts.push(`${report.volumes.length} volumes`);
+  return parts.join(", ");
+}
+
+/** How many distinct things `describeLeftovers` is describing — a container
+ *  and an image each count as one, however many volumes are named. Shared by
+ *  `leftoverVerb` and `leftoverPronoun` so the two can never disagree about
+ *  singular vs. plural. */
+function leftoverCount(report: ProjectRemovalReport): number {
+  return (report.container ? 1 : 0) + (report.image ? 1 : 0) + report.volumes.length;
+}
+
+/** Verb agreement for `describeLeftovers`'s output — "its container" needs
+ *  "was", "its container, a volume" needs "were". */
+export function leftoverVerb(report: ProjectRemovalReport): "was" | "were" {
+  return leftoverCount(report) === 1 ? "was" : "were";
+}
+
+/** Pronoun agreement for referring back to `describeLeftovers`'s output —
+ *  "remove it manually" for one thing, "remove them manually" for more. */
+export function leftoverPronoun(report: ProjectRemovalReport): "it" | "them" {
+  return leftoverCount(report) === 1 ? "it" : "them";
+}

app/src/components/settings/ExportSettingsModal.test.tsx

@@ -0,0 +1,72 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import ExportSettingsModal from "./ExportSettingsModal";
+
+const exportSettings = vi.fn();
+
+vi.mock("../../lib/tauri-commands", () => ({
+  exportSettings: (password: string) => exportSettings(password),
+}));
+
+beforeEach(() => {
+  vi.clearAllMocks();
+});
+
+function fillPasswords(password: string, confirm: string) {
+  fireEvent.change(screen.getByLabelText("Password"), { target: { value: password } });
+  fireEvent.change(screen.getByLabelText("Confirm password"), { target: { value: confirm } });
+}
+
+describe("ExportSettingsModal", () => {
+  it("keeps the submit button disabled until the passwords are long enough and match", () => {
+    render(<ExportSettingsModal onClose={vi.fn()} />);
+    const submit = screen.getByRole("button", { name: /choose where to save/i });
+    expect(submit).toBeDisabled();
+
+    fillPasswords("short", "short");
+    expect(submit).toBeDisabled();
+    expect(screen.getByText(/use at least 8 characters/i)).toBeInTheDocument();
+
+    fillPasswords("longenoughpassword", "different");
+    expect(submit).toBeDisabled();
+    expect(screen.getByText(/don't match/i)).toBeInTheDocument();
+
+    fillPasswords("longenoughpassword", "longenoughpassword");
+    expect(submit).not.toBeDisabled();
+  });
+
+  it("exports with the entered password and shows success", async () => {
+    exportSettings.mockResolvedValue(true);
+    render(<ExportSettingsModal onClose={vi.fn()} />);
+
+    fillPasswords("longenoughpassword", "longenoughpassword");
+    fireEvent.click(screen.getByRole("button", { name: /choose where to save/i }));
+
+    await waitFor(() => expect(exportSettings).toHaveBeenCalledWith("longenoughpassword"));
+    await waitFor(() => expect(screen.getByText(/settings exported/i)).toBeInTheDocument());
+  });
+
+  it("closes quietly when the save dialog is dismissed", async () => {
+    exportSettings.mockResolvedValue(false);
+    const onClose = vi.fn();
+    render(<ExportSettingsModal onClose={onClose} />);
+
+    fillPasswords("longenoughpassword", "longenoughpassword");
+    fireEvent.click(screen.getByRole("button", { name: /choose where to save/i }));
+
+    await waitFor(() => expect(onClose).toHaveBeenCalled());
+    expect(screen.queryByText(/settings exported/i)).not.toBeInTheDocument();
+  });
+
+  it("shows an error rather than closing when the export fails", async () => {
+    exportSettings.mockRejectedValue("Disk is full");
+    const onClose = vi.fn();
+    render(<ExportSettingsModal onClose={onClose} />);
+
+    fillPasswords("longenoughpassword", "longenoughpassword");
+    fireEvent.click(screen.getByRole("button", { name: /choose where to save/i }));
+
+    await waitFor(() => expect(screen.getByText("Disk is full")).toBeInTheDocument());
+    expect(onClose).not.toHaveBeenCalled();
+  });
+});

app/src/components/settings/ExportSettingsModal.tsx

@@ -0,0 +1,119 @@
+import { useState } from "react";
+import Modal from "../ui/Modal";
+import Button from "../ui/Button";
+import Field, { inputClass } from "../ui/Field";
+import { exportSettings } from "../../lib/tauri-commands";
+
+interface Props {
+  onClose: () => void;
+}
+
+const MIN_PASSWORD_LENGTH = 8;
+
+/**
+ * Password entry for exporting global settings. The save dialog itself opens
+ * from Rust once a password is confirmed here — see the doc comment on
+ * `commands::settings_export_commands` for why the host path never
+ * round-trips through this component.
+ */
+export default function ExportSettingsModal({ onClose }: Props) {
+  const [password, setPassword] = useState("");
+  const [confirmPassword, setConfirmPassword] = useState("");
+  const [busy, setBusy] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [done, setDone] = useState(false);
+
+  const mismatch = confirmPassword.length > 0 && password !== confirmPassword;
+  const tooShort = password.length > 0 && password.length < MIN_PASSWORD_LENGTH;
+  const canSubmit = password.length >= MIN_PASSWORD_LENGTH && password === confirmPassword;
+
+  const handleExport = async () => {
+    setError(null);
+    setBusy(true);
+    try {
+      const saved = await exportSettings(password);
+      if (saved) setDone(true);
+      // `false` means the save dialog was dismissed — close quietly, same as
+      // if the user had cancelled the modal itself.
+      else onClose();
+    } catch (e) {
+      setError(String(e));
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <Modal
+      title="Export settings"
+      description="Saves your global settings and any stored credentials (a shared Claude login, gateway keys) to one encrypted file. Project-specific settings and container data are not included."
+      widthClassName="w-[28rem]"
+      dismissible={!busy}
+      onClose={onClose}
+      footer={
+        done ? (
+          <Button size="md" variant="primary" onClick={onClose}>
+            Done
+          </Button>
+        ) : (
+          <>
+            <Button size="md" variant="ghost" onClick={onClose} disabled={busy}>
+              Cancel
+            </Button>
+            <Button
+              size="md"
+              variant="primary"
+              onClick={() => void handleExport()}
+              disabled={!canSubmit || busy}
+            >
+              {busy ? "Exporting…" : "Choose where to save…"}
+            </Button>
+          </>
+        )
+      }
+    >
+      {done ? (
+        <p className="text-[13px] text-[var(--success)]">
+          Settings exported. Keep the password somewhere safe — there is no way to recover
+          the file without it.
+        </p>
+      ) : (
+        <div className="space-y-3">
+          <Field label="Password" hint={`At least ${MIN_PASSWORD_LENGTH} characters. You'll need this exact password to import the file later.`}>
+            {(id) => (
+              <input
+                id={id}
+                type="password"
+                autoComplete="new-password"
+                value={password}
+                onChange={(e) => setPassword(e.target.value)}
+                disabled={busy}
+                className={inputClass}
+              />
+            )}
+          </Field>
+          <Field label="Confirm password">
+            {(id) => (
+              <input
+                id={id}
+                type="password"
+                autoComplete="new-password"
+                value={confirmPassword}
+                onChange={(e) => setConfirmPassword(e.target.value)}
+                disabled={busy}
+                className={inputClass}
+              />
+            )}
+          </Field>
+          {tooShort && (
+            <p className="text-xs text-[var(--error)]">
+              Use at least {MIN_PASSWORD_LENGTH} characters.
+            </p>
+          )}
+          {mismatch && <p className="text-xs text-[var(--error)]">Passwords don't match.</p>}
+          {error && <p className="text-xs text-[var(--error)]">{error}</p>}
+        </div>
+      )}
+    </Modal>
+  );
+}

app/src/components/settings/ImportSettingsModal.test.tsx

@@ -0,0 +1,145 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import ImportSettingsModal from "./ImportSettingsModal";
+import type { AppSettings, SettingsImportOutcome, SettingsImportPreview } from "../../lib/types";
+
+const previewSettingsImport = vi.fn();
+const applySettingsImport = vi.fn();
+
+vi.mock("../../lib/tauri-commands", () => ({
+  previewSettingsImport: (password: string) => previewSettingsImport(password),
+  applySettingsImport: (password: string) => applySettingsImport(password),
+}));
+
+beforeEach(() => {
+  vi.clearAllMocks();
+});
+
+const samplePreview: SettingsImportPreview = {
+  exported_at: "2026-08-27T00:00:00Z",
+  app_version: "0.4.14",
+  custom_env_var_count: 2,
+  gateway_model_count: 0,
+  has_claude_code_settings: false,
+  has_claude_oauth_token: true,
+  has_gateway_api_key: false,
+  has_gateway_master_key: false,
+  has_web_terminal_access_token: false,
+  enables_web_terminal: false,
+  ollama_base_url: null,
+  llamacpp_base_url: null,
+  openai_compatible_base_url: null,
+  gateway_api_base: null,
+  image_source: "registry",
+  custom_image_name: null,
+};
+
+function outcome(settings: AppSettings, secretRestoreWarnings: string[] = []): SettingsImportOutcome {
+  return { settings, secret_restore_warnings: secretRestoreWarnings };
+}
+
+describe("ImportSettingsModal", () => {
+  it("keeps 'Choose file' disabled until a password is entered", () => {
+    render(<ImportSettingsModal onClose={vi.fn()} onImported={vi.fn()} />);
+    expect(screen.getByRole("button", { name: /choose file/i })).toBeDisabled();
+
+    fireEvent.change(screen.getByLabelText("Password"), { target: { value: "hunter2" } });
+    expect(screen.getByRole("button", { name: /choose file/i })).not.toBeDisabled();
+  });
+
+  it("shows the preview and confirms with the same password used to open it", async () => {
+    previewSettingsImport.mockResolvedValue(samplePreview);
+    applySettingsImport.mockResolvedValue(outcome({} as AppSettings));
+    const onImported = vi.fn();
+    render(<ImportSettingsModal onClose={vi.fn()} onImported={onImported} />);
+
+    fireEvent.change(screen.getByLabelText("Password"), { target: { value: "hunter2" } });
+    fireEvent.click(screen.getByRole("button", { name: /choose file/i }));
+
+    await waitFor(() => expect(previewSettingsImport).toHaveBeenCalledWith("hunter2"));
+    expect(await screen.findByText(/2 global custom env vars/i)).toBeInTheDocument();
+    expect(screen.getByText(/your shared claude login/i)).toBeInTheDocument();
+
+    fireEvent.click(screen.getByRole("button", { name: /^import$/i }));
+    await waitFor(() => expect(applySettingsImport).toHaveBeenCalledWith("hunter2"));
+    await waitFor(() => expect(onImported).toHaveBeenCalledWith({}));
+    expect(await screen.findByText(/settings imported/i)).toBeInTheDocument();
+  });
+
+  it("shows a distinct warning when the import would enable the web terminal", async () => {
+    previewSettingsImport.mockResolvedValue({ ...samplePreview, enables_web_terminal: true });
+    render(<ImportSettingsModal onClose={vi.fn()} onImported={vi.fn()} />);
+
+    fireEvent.change(screen.getByLabelText("Password"), { target: { value: "hunter2" } });
+    fireEvent.click(screen.getByRole("button", { name: /choose file/i }));
+
+    expect(await screen.findByText(/enables the remote web terminal/i)).toBeInTheDocument();
+  });
+
+  it("warns about a custom Docker image every time, not just on change", async () => {
+    previewSettingsImport.mockResolvedValue({
+      ...samplePreview,
+      image_source: "custom",
+      custom_image_name: "ghcr.io/attacker/triple-c:latest",
+    });
+    render(<ImportSettingsModal onClose={vi.fn()} onImported={vi.fn()} />);
+
+    fireEvent.change(screen.getByLabelText("Password"), { target: { value: "hunter2" } });
+    fireEvent.click(screen.getByRole("button", { name: /choose file/i }));
+
+    expect(
+      await screen.findByText(/custom docker image: ghcr\.io\/attacker\/triple-c:latest/i),
+    ).toBeInTheDocument();
+  });
+
+  it("shows a secret-restore warning alongside success rather than hiding it", async () => {
+    previewSettingsImport.mockResolvedValue(samplePreview);
+    applySettingsImport.mockResolvedValue(
+      outcome({} as AppSettings, ["Could not restore the gateway master key: keychain locked"]),
+    );
+    render(<ImportSettingsModal onClose={vi.fn()} onImported={vi.fn()} />);
+
+    fireEvent.change(screen.getByLabelText("Password"), { target: { value: "hunter2" } });
+    fireEvent.click(screen.getByRole("button", { name: /choose file/i }));
+    await screen.findByText(/2 global custom env vars/i);
+
+    fireEvent.click(screen.getByRole("button", { name: /^import$/i }));
+    expect(await screen.findByText(/settings imported/i)).toBeInTheDocument();
+    expect(await screen.findByText(/could not restore the gateway master key/i)).toBeInTheDocument();
+  });
+
+  it("closes quietly when the file picker is dismissed", async () => {
+    previewSettingsImport.mockResolvedValue(null);
+    const onClose = vi.fn();
+    render(<ImportSettingsModal onClose={onClose} onImported={vi.fn()} />);
+
+    fireEvent.change(screen.getByLabelText("Password"), { target: { value: "hunter2" } });
+    fireEvent.click(screen.getByRole("button", { name: /choose file/i }));
+
+    await waitFor(() => expect(onClose).toHaveBeenCalled());
+  });
+
+  it("shows an error when the password is wrong rather than a blank preview", async () => {
+    previewSettingsImport.mockRejectedValue("Wrong password, or the file is corrupted.");
+    render(<ImportSettingsModal onClose={vi.fn()} onImported={vi.fn()} />);
+
+    fireEvent.change(screen.getByLabelText("Password"), { target: { value: "wrong" } });
+    fireEvent.click(screen.getByRole("button", { name: /choose file/i }));
+
+    expect(await screen.findByText(/wrong password, or the file is corrupted/i)).toBeInTheDocument();
+  });
+
+  it("shows an error if applying the import fails, without claiming success", async () => {
+    previewSettingsImport.mockResolvedValue(samplePreview);
+    applySettingsImport.mockRejectedValue("Keychain write failed");
+    render(<ImportSettingsModal onClose={vi.fn()} onImported={vi.fn()} />);
+
+    fireEvent.change(screen.getByLabelText("Password"), { target: { value: "hunter2" } });
+    fireEvent.click(screen.getByRole("button", { name: /choose file/i }));
+    await screen.findByText(/2 global custom env vars/i);
+
+    fireEvent.click(screen.getByRole("button", { name: /^import$/i }));
+    expect(await screen.findByText("Keychain write failed")).toBeInTheDocument();
+    expect(screen.queryByText(/settings imported/i)).not.toBeInTheDocument();
+  });
+});

app/src/components/settings/ImportSettingsModal.tsx

@@ -0,0 +1,166 @@
+import { useState } from "react";
+import Modal from "../ui/Modal";
+import Button from "../ui/Button";
+import Field, { inputClass } from "../ui/Field";
+import { applySettingsImport, previewSettingsImport } from "../../lib/tauri-commands";
+import { describeImport, describeImportWarnings } from "../../lib/settingsImportPreview";
+import type { AppSettings, SettingsImportPreview } from "../../lib/types";
+
+interface Props {
+  onClose: () => void;
+  /** Fired once the import is actually applied, so the caller can refresh
+   *  whatever reads settings from the store. */
+  onImported: (settings: AppSettings) => void;
+}
+
+/**
+ * Two phases: enter the password and pick the file (backend resolves the
+ * file dialog itself — see `commands::settings_export_commands`), then
+ * confirm a preview before anything is actually applied. The same password
+ * is reused for the second call rather than asking again; nothing about
+ * that call needs a fresh secret; the backend just doesn't cache the
+ * *decrypted payload* between the two.
+ */
+export default function ImportSettingsModal({ onClose, onImported }: Props) {
+  const [password, setPassword] = useState("");
+  const [busy, setBusy] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [preview, setPreview] = useState<SettingsImportPreview | null>(null);
+  const [applied, setApplied] = useState(false);
+  const [secretWarnings, setSecretWarnings] = useState<string[]>([]);
+
+  const handleChooseFile = async () => {
+    setError(null);
+    setBusy(true);
+    try {
+      const result = await previewSettingsImport(password);
+      if (result) setPreview(result);
+      else onClose(); // File picker dismissed.
+    } catch (e) {
+      setError(String(e));
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  const handleConfirm = async () => {
+    setError(null);
+    setBusy(true);
+    try {
+      const outcome = await applySettingsImport(password);
+      setApplied(true);
+      setSecretWarnings(outcome.secret_restore_warnings);
+      onImported(outcome.settings);
+    } catch (e) {
+      setError(String(e));
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <Modal
+      title="Import settings"
+      description={
+        preview
+          ? "Review what this file will change before applying it."
+          : "Choose a Triple-C settings export and enter the password it was created with."
+      }
+      widthClassName="w-[28rem]"
+      dismissible={!busy}
+      onClose={onClose}
+      footer={
+        applied ? (
+          <Button size="md" variant="primary" onClick={onClose}>
+            Done
+          </Button>
+        ) : preview ? (
+          <>
+            <Button size="md" variant="ghost" onClick={onClose} disabled={busy}>
+              Cancel
+            </Button>
+            <Button size="md" variant="primary" onClick={() => void handleConfirm()} disabled={busy}>
+              {busy ? "Importing…" : "Import"}
+            </Button>
+          </>
+        ) : (
+          <>
+            <Button size="md" variant="ghost" onClick={onClose} disabled={busy}>
+              Cancel
+            </Button>
+            <Button
+              size="md"
+              variant="primary"
+              onClick={() => void handleChooseFile()}
+              disabled={!password || busy}
+            >
+              {busy ? "Opening…" : "Choose file…"}
+            </Button>
+          </>
+        )
+      }
+    >
+      {applied ? (
+        <div className="space-y-2">
+          <p className="text-[13px] text-[var(--success)]">Settings imported.</p>
+          {secretWarnings.map((warning) => (
+            <p
+              key={warning}
+              className="px-2.5 py-2 text-xs text-[var(--error)] bg-[var(--error-muted)] border border-[var(--error)]/40 rounded-[var(--radius-control)] leading-snug"
+            >
+              {warning}
+            </p>
+          ))}
+        </div>
+      ) : preview ? (
+        <div className="space-y-3">
+          <p className="text-xs text-[var(--text-secondary)]">
+            Exported {new Date(preview.exported_at).toLocaleString()} from Triple-C{" "}
+            {preview.app_version}.
+          </p>
+          {/* Warnings render before the replace list, deliberately: the list
+           *  below can run long, and the one thing here that most needs to
+           *  stay above the fold while scrolling is "this turns on a
+           *  network-listening service" or "this runs a different image" —
+           *  not a bullet buried among ordinary settings. */}
+          {describeImportWarnings(preview).map((warning) => (
+            <p
+              key={warning}
+              className="px-2.5 py-2 text-xs text-[var(--warning)] bg-[var(--warning-muted)] border border-[var(--warning)]/40 rounded-[var(--radius-control)] leading-snug break-all"
+            >
+              {warning}
+            </p>
+          ))}
+          <div>
+            <p className="text-[13px] font-medium text-[var(--text-primary)]">This will replace:</p>
+            <ul className="mt-1 list-disc pl-4 text-[13px] text-[var(--text-secondary)] space-y-0.5">
+              {describeImport(preview).map((item) => (
+                <li key={item} className="break-all">
+                  {item}
+                </li>
+              ))}
+            </ul>
+          </div>
+          {error && <p className="text-xs text-[var(--error)]">{error}</p>}
+        </div>
+      ) : (
+        <div className="space-y-3">
+          <Field label="Password">
+            {(id) => (
+              <input
+                id={id}
+                type="password"
+                autoComplete="current-password"
+                value={password}
+                onChange={(e) => setPassword(e.target.value)}
+                disabled={busy}
+                className={inputClass}
+              />
+            )}
+          </Field>
+          {error && <p className="text-xs text-[var(--error)]">{error}</p>}
+        </div>
+      )}
+    </Modal>
+  );
+}

app/src/components/settings/SettingsPanel.tsx

@@ -15,13 +15,17 @@ import type { EnvVar } from "../../lib/types";
 import Tooltip from "../ui/Tooltip";
 import AccordionSection from "../ui/AccordionSection";
 import Toggle from "../ui/Toggle";
+import SegmentedControl from "../ui/SegmentedControl";
+import { resolveTerminalGpuRendering } from "../../lib/terminalRenderer";
 import WebTerminalSettings from "./WebTerminalSettings";
 import SttSettings from "./SttSettings";
 import SharedAuthSettings from "./SharedAuthSettings";
 import CertificateSettings from "./CertificateSettings";
+import ExportSettingsModal from "./ExportSettingsModal";
+import ImportSettingsModal from "./ImportSettingsModal";
 
 export default function SettingsPanel() {
-  const { appSettings, saveSettings } = useSettings();
+  const { appSettings, saveSettings, setAppSettings } = useSettings();
   const { appVersion, imageUpdateInfo, checkForUpdates, checkImageUpdate } = useUpdates();
   const [globalInstructions, setGlobalInstructions] = useState(appSettings?.global_claude_instructions ?? "");
   const [globalEnvVars, setGlobalEnvVars] = useState<EnvVar[]>(appSettings?.global_custom_env_vars ?? []);
@@ -33,6 +37,8 @@ export default function SettingsPanel() {
   const [showInstructionsModal, setShowInstructionsModal] = useState(false);
   const [showEnvVarsModal, setShowEnvVarsModal] = useState(false);
   const [showClaudeCodeSettingsModal, setShowClaudeCodeSettingsModal] = useState(false);
+  const [showExportModal, setShowExportModal] = useState(false);
+  const [showImportModal, setShowImportModal] = useState(false);
 
   // Sync local state when appSettings change
   useEffect(() => {
@@ -63,6 +69,14 @@ export default function SettingsPanel() {
     }
   };
 
+  const handleGpuRenderingChange = async (value: "auto" | "on" | "off") => {
+    if (!appSettings) return;
+    await saveSettings({
+      ...appSettings,
+      terminal_gpu_rendering: value === "auto" ? null : value === "on",
+    });
+  };
+
   const handleAutoCheckToggle = async () => {
     if (!appSettings) return;
     await saveSettings({ ...appSettings, auto_check_updates: !appSettings.auto_check_updates });
@@ -238,6 +252,45 @@ export default function SettingsPanel() {
         <SttSettings />
       </AccordionSection>
 
+      <AccordionSection id="terminal" title="Terminal" defaultOpen={false}>
+        <div className="space-y-2">
+          <label className="text-xs text-[var(--text-secondary)]">GPU rendering</label>
+          <SegmentedControl
+            label="Terminal GPU rendering"
+            value={
+              appSettings?.terminal_gpu_rendering == null
+                ? "auto"
+                : appSettings.terminal_gpu_rendering
+                  ? "on"
+                  : "off"
+            }
+            onChange={handleGpuRenderingChange}
+            segments={[
+              {
+                value: "auto",
+                label: "Auto",
+                hint: resolveTerminalGpuRendering(null, navigator.userAgent)
+                  ? "On for this platform."
+                  : "Off on Linux — the DMA-BUF workaround leaves WebGL on software rendering, which is slower than the canvas renderer.",
+              },
+              {
+                value: "on",
+                label: "On",
+                hint: "Always load the WebGL renderer.",
+              },
+              {
+                value: "off",
+                label: "Off",
+                hint: "Always use xterm's canvas renderer. Try this if typing feels laggy.",
+              },
+            ]}
+          />
+          <p className="text-xs text-[var(--text-secondary)]">
+            Takes effect when a terminal tab is next switched to.
+          </p>
+        </div>
+      </AccordionSection>
+
       <AccordionSection id="updates" title="Updates" defaultOpen={false}>
         <div className="space-y-2">
           {appVersion && (
@@ -269,6 +322,39 @@ export default function SettingsPanel() {
         </div>
       </AccordionSection>
 
+      <AccordionSection id="backup" title="Backup" defaultOpen={false}>
+        <div className="space-y-2">
+          <p className="text-xs text-[var(--text-secondary)] leading-snug">
+            Export your global settings and stored credentials (a shared Claude login,
+            gateway keys) to one password-encrypted file, or restore them on a new machine.
+            Project-specific settings and container data are never included.
+          </p>
+          <div className="flex gap-2">
+            <button
+              onClick={() => setShowExportModal(true)}
+              className="px-3 py-1.5 text-xs bg-[var(--bg-primary)] border border-[var(--border-color)] rounded hover:bg-[var(--border-color)] transition-colors"
+            >
+              Export settings…
+            </button>
+            <button
+              onClick={() => setShowImportModal(true)}
+              className="px-3 py-1.5 text-xs bg-[var(--bg-primary)] border border-[var(--border-color)] rounded hover:bg-[var(--border-color)] transition-colors"
+            >
+              Import settings…
+            </button>
+          </div>
+        </div>
+      </AccordionSection>
+
+      {showExportModal && <ExportSettingsModal onClose={() => setShowExportModal(false)} />}
+
+      {showImportModal && (
+        <ImportSettingsModal
+          onClose={() => setShowImportModal(false)}
+          onImported={(settings) => setAppSettings(settings)}
+        />
+      )}
+
       {showInstructionsModal && (
         <ClaudeInstructionsModal
           instructions={globalInstructions}

app/src/components/terminal/TerminalView.test.tsx

@@ -137,19 +137,36 @@ afterEach(() => {
 });
 
 describe("TerminalView — Shift+Enter", () => {
-  it("sends ESC+CR and nothing else in a Claude session", () => {
+  it("sends ESC+CR and cancels the keydown, so no bare CR follows", () => {
+    // **The cancel is the load-bearing half, and this test could not see it.**
+    //
+    // Returning `false` from xterm's custom key handler does not cancel the
+    // event: `_keyDown` returns before setting `_keyDownHandled`, so
+    // `_keyPress` still runs and emits a bare CR for Enter's charCode 13. In a
+    // real browser that submitted the prompt straight after inserting the
+    // newline. jsdom never synthesizes the follow-up keypress, so the old
+    // `expect(sent()).not.toContain("\r")` assertion below could not fail no
+    // matter what the code did — it was named for a behaviour it could not
+    // exercise.
+    //
+    // Asserting `defaultPrevented` pins the actual mechanism that stops the
+    // keypress, which is a property jsdom *can* observe.
     const { container } = mountSession("claude");
 
-    fireEvent.keyDown(helperTextarea(container), {
+    const event = new KeyboardEvent("keydown", {
       key: "Enter",
       keyCode: 13,
       shiftKey: true,
+      bubbles: true,
+      cancelable: true,
     });
+    helperTextarea(container).dispatchEvent(event);
 
     // The bytes `/terminal-setup` installs for every other editor.
     expect(sent()).toEqual(["\x1b\r"]);
-    // And specifically not the bare CR that would have submitted the prompt.
     expect(sent()).not.toContain("\r");
+    // Without this, the browser fires keypress and xterm submits.
+    expect(event.defaultPrevented).toBe(true);
   });
 
   it("leaves a plain Enter alone", () => {

app/src/components/terminal/TerminalView.tsx

@@ -28,6 +28,7 @@ import UrlToast, {
   URL_TOAST_SHORTCUT,
 } from "./UrlToast";
 import { trimSelection } from "./trimSelection";
+import { resolveTerminalGpuRendering } from "../../lib/terminalRenderer";
 import TerminalContextMenu from "./TerminalContextMenu";
 
 interface Props {
@@ -95,6 +96,7 @@ export default function TerminalView({ sessionId, active }: Props) {
   const webglRef = useRef<WebglAddon | null>(null);
   const detectorRef = useRef<UrlDetector | null>(null);
   const { sendInput, pasteImage, resize, onOutput, onExit } = useTerminal();
+  const gpuRenderingSetting = useAppState(s => s.appSettings?.terminal_gpu_rendering ?? null);
   const setTerminalHasSelection = useAppState(s => s.setTerminalHasSelection);
   const setTerminalAtBottom = useAppState(s => s.setTerminalAtBottom);
   const setScrollActiveToBottom = useAppState(s => s.setScrollActiveToBottom);
@@ -414,7 +416,19 @@ export default function TerminalView({ sessionId, active }: Props) {
         sessionTypeRef.current === "claude"
       ) {
         sendInput(sessionId, "\x1b\r");
-        return false; // xterm must not also send a bare CR, which submits
+        // **`preventDefault()` is what stops the submit, not the `return false`.**
+        //
+        // xterm's `_keyDown` returns the instant a custom handler says `false`
+        // — *before* it sets `_keyDownHandled` and before it cancels the event.
+        // `_keyPress` then checks that same flag, finds it still false, and
+        // emits a bare CR for Enter's charCode 13. So returning `false` alone
+        // sent ESC+CR *and* a submit: the newline was inserted and the
+        // half-written prompt went to Claude with a stray blank line in it.
+        // Cancelling the keydown is what stops the browser firing keypress at
+        // all. Verified in Chromium; jsdom never synthesizes the follow-up
+        // keypress, which is why the unit test could not see this.
+        event.preventDefault();
+        return false;
       }
       return true;
     });
@@ -479,7 +493,11 @@ export default function TerminalView({ sessionId, active }: Props) {
 
     // Handle user input -> backend
     const inputDisposable = term.onData((data) => {
-      sendInput(sessionId, data);
+      // Ordered and coalesced by the queue in `useTerminal`; a rejection here
+      // means the session is gone, which the exit listener already reports.
+      sendInput(sessionId, data).catch((e) =>
+        console.error("Failed to send terminal input:", e)
+      );
     });
 
     // Detect user-initiated scroll-up (mouse wheel) to pause auto-follow.
@@ -672,7 +690,16 @@ export default function TerminalView({ sessionId, active }: Props) {
     const term = termRef.current;
     if (!term) return;
 
-    if (active) {
+    // Auto on macOS/Windows, off on Linux, overridable either way — see
+    // `resolveTerminalGpuRendering`. Loading the addon under a software-GL
+    // WebKitGTK is slower than xterm's canvas renderer, not faster.
+    const useGpu = resolveTerminalGpuRendering(gpuRenderingSetting, navigator.userAgent);
+
+    // The renderer and the activation work are independent: a terminal with
+    // GPU rendering switched off still has to fit and take focus when its tab
+    // becomes active. Keeping these in one branch made "GPU off" silently mean
+    // "never re-fit, never focus".
+    if (active && useGpu) {
       // Attach WebGL renderer
       if (!webglRef.current) {
         try {
@@ -687,19 +714,21 @@ export default function TerminalView({ sessionId, active }: Props) {
           // WebGL not available, canvas renderer is fine
         }
       }
+    } else if (webglRef.current) {
+      // Release the context — for inactive terminals, and when the setting
+      // turns GPU rendering off while this terminal is on screen.
+      try { webglRef.current.dispose(); } catch { /* ignore */ }
+      webglRef.current = null;
+    }
+
+    if (active) {
       fitRef.current?.fit();
       if (autoFollowRef.current) {
         term.scrollToBottom();
       }
       term.focus();
-    } else {
-      // Release WebGL context for inactive terminals
-      if (webglRef.current) {
-        try { webglRef.current.dispose(); } catch { /* ignore */ }
-        webglRef.current = null;
     }
-    }
-  }, [active]);
+  }, [active, gpuRenderingSetting]);
 
   // Auto-dismiss toast after 30 seconds — unless the user is standing in it.
   // A keyboard user who has just jumped into the toast is mid-decision, and

app/src/components/ui/Button.test.tsx

@@ -0,0 +1,77 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent } from "@testing-library/react";
+import Button from "./Button";
+
+const onClick = vi.fn();
+const onKeyDown = vi.fn();
+
+describe("Button", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("still supports the native disabled attribute", () => {
+    render(
+      <Button disabled onClick={onClick}>
+        Save
+      </Button>,
+    );
+    expect(screen.getByRole("button", { name: "Save" })).toBeDisabled();
+  });
+
+  it("stays in the accessibility tree when unavailable, and says why", () => {
+    render(
+      <Button unavailable unavailableReason="Stop the container first.">
+        Save
+      </Button>,
+    );
+    const button = screen.getByRole("button", { name: "Save" });
+    expect(button).not.toBeDisabled();
+    expect(button).toHaveAttribute("aria-disabled", "true");
+    expect(button).toHaveAccessibleDescription("Stop the container first.");
+    // The reason is a description, not part of the name.
+    expect(button).toHaveAccessibleName("Save");
+  });
+
+  it("guards clicks and Enter/Space while unavailable", () => {
+    render(
+      <Button unavailable unavailableReason="Stop the container first." onClick={onClick}>
+        Save
+      </Button>,
+    );
+    const button = screen.getByRole("button", { name: "Save" });
+    fireEvent.click(button);
+    fireEvent.keyDown(button, { key: "Enter" });
+    fireEvent.keyDown(button, { key: " " });
+    expect(onClick).not.toHaveBeenCalled();
+  });
+
+  it("still forwards keys that are not activation keys", () => {
+    render(
+      <Button
+        unavailable
+        unavailableReason="Stop the container first."
+        onKeyDown={onKeyDown}
+      >
+        Save
+      </Button>,
+    );
+    fireEvent.keyDown(screen.getByRole("button", { name: "Save" }), {
+      key: "Escape",
+    });
+    expect(onKeyDown).toHaveBeenCalled();
+  });
+
+  it("behaves like an ordinary button when available", () => {
+    render(
+      <Button unavailable={false} unavailableReason="Stop the container first." onClick={onClick}>
+        Save
+      </Button>,
+    );
+    const button = screen.getByRole("button", { name: "Save" });
+    expect(button).not.toHaveAttribute("aria-disabled");
+    expect(button).toHaveAccessibleDescription("");
+    fireEvent.click(button);
+    expect(onClick).toHaveBeenCalledTimes(1);
+  });
+});

app/src/components/ui/Button.tsx

@@ -1,4 +1,5 @@
 import type { ButtonHTMLAttributes, ReactNode } from "react";
+import { useUnavailable } from "./unavailable";
 
 export type ButtonVariant = "primary" | "secondary" | "danger" | "ghost";
 export type ButtonSize = "sm" | "md";
@@ -7,22 +8,37 @@ interface Props extends ButtonHTMLAttributes<HTMLButtonElement> {
   variant?: ButtonVariant;
   size?: ButtonSize;
   children: ReactNode;
+  /**
+   * Unavailable, but still announced. Renders `aria-disabled` and wires
+   * `unavailableReason` to `aria-describedby` instead of using the native
+   * `disabled` attribute, which would take the button out of the tab order and
+   * out of the accessibility tree — reason and all. Clicks and Enter/Space are
+   * guarded for you. Prefer this over `disabled` whenever there is a reason
+   * worth telling the user.
+   */
+  unavailable?: boolean;
+  /** Why the button cannot be used. Required for `unavailable` to say anything. */
+  unavailableReason?: string;
 }
 
 /**
  * Real buttons with visible bounds and a ≥24px hit target.
  * Filled variants use the *-emphasis tokens so white text clears WCAG AA;
  * `--accent` stays reserved for foreground/link use.
+ *
+ * The `aria-disabled:` class mirrors below exist because Tailwind's
+ * `disabled:` variant only matches the native attribute, which `unavailable`
+ * deliberately does not set. Keep the two lists in step.
  */
 const VARIANTS: Record<ButtonVariant, string> = {
   primary:
-    "bg-[var(--accent-emphasis)] text-white border border-transparent hover:bg-[var(--accent-emphasis-hover)] disabled:bg-[var(--bg-tertiary)] disabled:text-[var(--text-disabled)] disabled:border-[var(--border-color)]",
+    "bg-[var(--accent-emphasis)] text-white border border-transparent hover:bg-[var(--accent-emphasis-hover)] disabled:bg-[var(--bg-tertiary)] disabled:text-[var(--text-disabled)] disabled:border-[var(--border-color)] aria-disabled:bg-[var(--bg-tertiary)] aria-disabled:text-[var(--text-disabled)] aria-disabled:border-[var(--border-color)] aria-disabled:hover:bg-[var(--bg-tertiary)]",
   secondary:
-    "bg-[var(--bg-tertiary)] text-[var(--text-primary)] border border-[var(--border-color)] hover:bg-[var(--border-color)] disabled:text-[var(--text-disabled)] disabled:hover:bg-[var(--bg-tertiary)]",
+    "bg-[var(--bg-tertiary)] text-[var(--text-primary)] border border-[var(--border-color)] hover:bg-[var(--border-color)] disabled:text-[var(--text-disabled)] disabled:hover:bg-[var(--bg-tertiary)] aria-disabled:text-[var(--text-disabled)] aria-disabled:hover:bg-[var(--bg-tertiary)]",
   danger:
-    "bg-transparent text-[var(--error)] border border-[var(--error)]/40 hover:bg-[var(--error-muted)] disabled:text-[var(--text-disabled)] disabled:border-[var(--border-color)] disabled:hover:bg-transparent",
+    "bg-transparent text-[var(--error)] border border-[var(--error)]/40 hover:bg-[var(--error-muted)] disabled:text-[var(--text-disabled)] disabled:border-[var(--border-color)] disabled:hover:bg-transparent aria-disabled:text-[var(--text-disabled)] aria-disabled:border-[var(--border-color)] aria-disabled:hover:bg-transparent",
   ghost:
-    "bg-transparent text-[var(--text-secondary)] border border-transparent hover:text-[var(--text-primary)] hover:bg-[var(--bg-tertiary)] disabled:text-[var(--text-disabled)] disabled:hover:bg-transparent",
+    "bg-transparent text-[var(--text-secondary)] border border-transparent hover:text-[var(--text-primary)] hover:bg-[var(--bg-tertiary)] disabled:text-[var(--text-disabled)] disabled:hover:bg-transparent aria-disabled:text-[var(--text-disabled)] aria-disabled:hover:text-[var(--text-disabled)] aria-disabled:hover:bg-transparent",
 };
 
 const SIZES: Record<ButtonSize, string> = {
@@ -35,16 +51,30 @@ export default function Button({
   size = "sm",
   className = "",
   type = "button",
+  unavailable = false,
+  unavailableReason = "",
   children,
   ...rest
 }: Props) {
+  const { controlProps, reasonNode } = useUnavailable({
+    unavailable,
+    reason: unavailableReason,
+    onClick: rest.onClick,
+    onKeyDown: rest.onKeyDown,
+  });
+
   return (
+    <>
       <button
         type={type}
         {...rest}
-      className={`inline-flex items-center justify-center whitespace-nowrap rounded-[var(--radius-control)] font-medium transition-colors disabled:cursor-not-allowed ${SIZES[size]} ${VARIANTS[variant]} ${className}`}
+        {...controlProps}
+        className={`inline-flex items-center justify-center whitespace-nowrap rounded-[var(--radius-control)] font-medium transition-colors disabled:cursor-not-allowed aria-disabled:cursor-not-allowed ${SIZES[size]} ${VARIANTS[variant]} ${className}`}
       >
         {children}
       </button>
+      {/* Outside the button: inside, the reason would join its accessible name. */}
+      {reasonNode}
+    </>
   );
 }

app/src/components/ui/ToastHost.tsx

@@ -47,7 +47,16 @@ function ToastCard({ toast, onDismiss }: { toast: Toast; onDismiss: () => void }
         {tone.glyph}
       </span>
       <div className="flex-1 min-w-0">
-        <div className="text-[var(--text-primary)] break-words">{toast.message}</div>
+        {/* Clamped. A toast message is normally a sentence, but some of them
+            quote text a *container* wrote — and this card is `z-[60]`, above
+            every modal, with its dismiss button at the top. An unclamped
+            message of a few kilobytes is a card taller than the viewport whose
+            ✕ has been pushed off-screen, i.e. an unclosable overlay. The
+            `detail` block below has always had `max-h-40 overflow-auto`; this
+            half did not. */}
+        <div className="text-[var(--text-primary)] break-words max-h-40 overflow-y-auto">
+          {toast.message}
+        </div>
         {toast.detail && (
           <>
             <button

app/src/components/ui/unavailable.tsx

@@ -0,0 +1,87 @@
+import {
+  useId,
+  type KeyboardEventHandler,
+  type MouseEventHandler,
+  type ReactNode,
+} from "react";
+
+/** Keys a native `<button>` turns into a click. */
+const ACTIVATION_KEYS = new Set([" ", "Spacebar", "Enter"]);
+
+export interface UnavailableControlProps {
+  "aria-disabled"?: true;
+  "aria-describedby"?: string;
+  onClick?: MouseEventHandler<HTMLButtonElement>;
+  onKeyDown?: KeyboardEventHandler<HTMLButtonElement>;
+}
+
+export interface UnavailableControl {
+  /** Spread onto the control. Carries the guarded handlers. */
+  controlProps: UnavailableControlProps;
+  /**
+   * Render as a *sibling* of the control — inside it the reason would be
+   * appended to the accessible name instead of the description.
+   */
+  reasonNode: ReactNode;
+}
+
+/**
+ * Makes a control unavailable without hiding it from assistive technology.
+ *
+ * `disabled` takes an element out of the tab order *and* out of the
+ * accessibility tree, so the `title` explaining why it cannot be used is
+ * announced to nobody and shown only to a sighted user with a mouse. That is
+ * backwards: the people who most need the reason are the ones who never get
+ * it. `aria-disabled` keeps the control focusable and announced, and
+ * `aria-describedby` hands over the reason.
+ *
+ * The catch is that `aria-disabled` is advisory — it does not block clicks or
+ * Enter/Space the way `disabled` does. This hook therefore returns the guards
+ * along with the attributes, so a call site cannot take the announcement
+ * without the guard. Handlers that a form can reach without going through the
+ * control (Enter inside a text field submits the form) still have to guard
+ * themselves.
+ */
+export function useUnavailable({
+  unavailable,
+  reason,
+  onClick,
+  onKeyDown,
+}: {
+  unavailable: boolean;
+  reason: string;
+  onClick?: MouseEventHandler<HTMLButtonElement>;
+  onKeyDown?: KeyboardEventHandler<HTMLButtonElement>;
+}): UnavailableControl {
+  const reasonId = `${useId()}unavailable`;
+
+  if (!unavailable) {
+    return { controlProps: { onClick, onKeyDown }, reasonNode: null };
+  }
+
+  return {
+    controlProps: {
+      "aria-disabled": true,
+      "aria-describedby": reasonId,
+      onClick: (e) => {
+        e.preventDefault();
+        e.stopPropagation();
+      },
+      onKeyDown: (e) => {
+        if (!ACTIVATION_KEYS.has(e.key)) {
+          onKeyDown?.(e);
+          return;
+        }
+        // Suppress the default action before it can become a click, submit a
+        // form, or scroll the page.
+        e.preventDefault();
+        e.stopPropagation();
+      },
+    },
+    reasonNode: (
+      <span id={reasonId} className="sr-only">
+        {reason}
+      </span>
+    ),
+  };
+}

app/src/hooks/useFileManager.test.ts

@@ -6,12 +6,16 @@ import type { FileEntry } from "../lib/types";
 const listContainerFiles = vi.fn();
 const renameContainerPath = vi.fn();
 const createContainerDirectory = vi.fn();
+const uploadFilesToContainer = vi.fn();
+const downloadContainerFile = vi.fn();
 
 vi.mock("../lib/tauri-commands", () => ({
   listContainerFiles: (p: string, path: string) => listContainerFiles(p, path),
   renameContainerPath: (p: string, f: string, t: string) => renameContainerPath(p, f, t),
   createContainerDirectory: (p: string, parent: string, n: string) =>
     createContainerDirectory(p, parent, n),
+  uploadFilesToContainer: (p: string, dir: string) => uploadFilesToContainer(p, dir),
+  downloadContainerFile: (p: string, path: string) => downloadContainerFile(p, path),
   readContainerFile: vi.fn(),
 }));
 
@@ -45,6 +49,8 @@ const file = (name: string, extra: Partial<FileEntry> = {}): FileEntry => ({
 beforeEach(() => {
   vi.clearAllMocks();
   listContainerFiles.mockResolvedValue([file("a.txt")]);
+  uploadFilesToContainer.mockResolvedValue({ uploaded: [], failures: [] });
+  downloadContainerFile.mockResolvedValue(0);
 });
 
 describe("useFileManager navigation", () => {
@@ -292,3 +298,264 @@ describe("useFileManager surfaces written refusals as prose", () => {
     expect(lastToast().detail).toBe("no space left on device");
   });
 });
+
+/**
+ * Both of these actions are *dialog-driven from Rust* — the hook passes a
+ * project and a directory and gets back an answer, and there is deliberately no
+ * host path anywhere in this file. What is worth pinning is the vocabulary of
+ * that answer, because two of its values look like failure and are not: `null`
+ * means the user dismissed the picker, and `0` bytes means an empty file was
+ * saved successfully.
+ */
+describe("useFileManager saving to the host", () => {
+  it("treats a zero-byte save as a success", async () => {
+    // The bug this exists for: `if (!bytes) return` reads a genuine
+    // zero-length file — an empty `.gitkeep`, a truncated log — as a
+    // dismissal, so the file lands on the host and the app says nothing at
+    // all. The sentinel is `null`, and only `null`.
+    downloadContainerFile.mockResolvedValueOnce(0);
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.saveToHost(file("empty.txt"));
+    });
+    expect(result.current.completed).toContain("empty.txt");
+    expect(pushToast).not.toHaveBeenCalled();
+  });
+
+  it("says nothing at all when the dialog is dismissed", async () => {
+    downloadContainerFile.mockResolvedValueOnce(null);
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.saveToHost(file("a.txt"));
+    });
+    expect(result.current.completed).toBeNull();
+    expect(pushToast).not.toHaveBeenCalled();
+  });
+
+  it("names the file in a refusal", async () => {
+    downloadContainerFile.mockRejectedValueOnce("/etc/shadow is not readable");
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.saveToHost(file("secret.txt"));
+    });
+    expect(toastText()).toContain("secret.txt");
+  });
+});
+
+describe("useFileManager uploading from the host", () => {
+  it("uploads into the directory on screen and shows the result", async () => {
+    uploadFilesToContainer.mockResolvedValueOnce({
+      uploaded: ["/workspace/app/one.txt", "/workspace/app/two.txt"],
+      failures: [],
+    });
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.navigate("/workspace/app");
+    });
+    listContainerFiles.mockClear();
+    await act(async () => {
+      await result.current.uploadFiles();
+    });
+    expect(uploadFilesToContainer).toHaveBeenCalledWith("p1", "/workspace/app");
+    expect(result.current.completed).toContain("2 files");
+    // The directory is named. `target` is captured at click time and the
+    // picker is a modal dialog, so "Uploaded 2 files." on its own can be shown
+    // in front of a grid those files are not in.
+    expect(result.current.completed).toContain("/workspace/app");
+    // The new files are only on screen if the listing was asked for again.
+    expect(listContainerFiles).toHaveBeenCalledWith("p1", "/workspace/app");
+  });
+
+  it("reports every file that failed, not just a count", async () => {
+    // "3 of 5 uploaded" without naming the two is not a report — the user
+    // cannot tell which ones to retry, or why.
+    uploadFilesToContainer.mockResolvedValueOnce({
+      uploaded: ["/workspace/ok.txt"],
+      failures: [
+        "/home/j/Pictures is a folder — upload its files individually.",
+        "/home/j/vm.img is too large to upload (900 MB; limit 256 MB).",
+      ],
+    });
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.uploadFiles();
+    });
+    expect(pushToast).toHaveBeenCalledTimes(2);
+    expect(toastText()).toContain("is a folder");
+    expect(toastText()).toContain("too large");
+    // A partial batch still succeeded partially, and the pane must show it.
+    expect(result.current.completed).toContain("1 file");
+  });
+
+  it("does not refresh when the picker was dismissed", async () => {
+    uploadFilesToContainer.mockResolvedValueOnce(null);
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.navigate("/workspace/app");
+    });
+    listContainerFiles.mockClear();
+    await act(async () => {
+      await result.current.uploadFiles();
+    });
+    expect(listContainerFiles).not.toHaveBeenCalled();
+    expect(pushToast).not.toHaveBeenCalled();
+    expect(result.current.completed).toBeNull();
+  });
+
+  it("reports a refusal that happened before the picker once, not per file", async () => {
+    // No container, not running, or a directory this pane may not write to.
+    // There is no selection yet, so there is nothing to enumerate.
+    uploadFilesToContainer.mockRejectedValueOnce(
+      "Start the project before uploading files — it runs inside the running container.",
+    );
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.uploadFiles();
+    });
+    expect(pushToast).toHaveBeenCalledTimes(1);
+    expect(toastText()).toContain("Start the project");
+  });
+
+  it("does not drag the pane back when the user navigated during the upload", async () => {
+    // The same rule rename and new-folder follow: a slow operation must not
+    // relist a directory the user has already left.
+    let release: (v: unknown) => void = () => {};
+    uploadFilesToContainer.mockReturnValueOnce(
+      new Promise((resolve) => {
+        release = resolve;
+      }),
+    );
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.navigate("/workspace/app");
+    });
+    let uploading: Promise<void>;
+    act(() => {
+      uploading = result.current.uploadFiles();
+    });
+    await act(async () => {
+      await result.current.navigate("/workspace/other");
+    });
+    listContainerFiles.mockClear();
+    await act(async () => {
+      release({ uploaded: ["/workspace/app/one.txt"], failures: [] });
+      await uploading;
+    });
+    expect(listContainerFiles).not.toHaveBeenCalled();
+    expect(result.current.currentPath).toBe("/workspace/other");
+  });
+});
+
+describe("useFileManager transfer state", () => {
+  it("marks an upload in flight for as long as it runs", async () => {
+    // Without this the button stays live: a second click opens a second OS
+    // dialog and runs a second concurrent exec, and a slow transfer looks
+    // exactly like a click that did nothing.
+    let release: (v: unknown) => void = () => {};
+    uploadFilesToContainer.mockReturnValueOnce(
+      new Promise((resolve) => {
+        release = resolve;
+      }),
+    );
+    const { result } = renderHook(() => useFileManager("p1"));
+    expect(result.current.uploading).toBe(false);
+    let uploading: Promise<void>;
+    act(() => {
+      uploading = result.current.uploadFiles();
+    });
+    expect(result.current.uploading).toBe(true);
+    await act(async () => {
+      release({ uploaded: [], failures: [] });
+      await uploading;
+    });
+    expect(result.current.uploading).toBe(false);
+  });
+
+  it("stays in flight through the refresh, not just the transfer", async () => {
+    // Clearing the flag the moment the command settled put the button back
+    // while the re-listing was still running, so a second click landed
+    // mid-refresh on a grid that was still showing the old contents.
+    uploadFilesToContainer.mockResolvedValueOnce({
+      uploaded: ["/workspace/a.txt"],
+      failures: [],
+    });
+    let finishListing: (v: unknown) => void = () => {};
+    listContainerFiles.mockReturnValueOnce(
+      new Promise((resolve) => {
+        finishListing = resolve;
+      }),
+    );
+    const { result } = renderHook(() => useFileManager("p1"));
+    let uploading: Promise<void>;
+    act(() => {
+      uploading = result.current.uploadFiles();
+    });
+    await act(async () => {
+      await Promise.resolve();
+      await Promise.resolve();
+    });
+    // The transfer is done; the listing it triggered is not.
+    expect(result.current.uploading).toBe(true);
+    await act(async () => {
+      finishListing([file("a.txt")]);
+      await uploading;
+    });
+    expect(result.current.uploading).toBe(false);
+  });
+
+  it("clears the upload flag when the transfer fails", async () => {
+    // The `catch` returns early, so without a `finally` the button is disabled
+    // for the rest of the session — the failure mode is a pane that can never
+    // upload again, with no error left on screen to explain it.
+    uploadFilesToContainer.mockRejectedValueOnce("Start the project first");
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.uploadFiles();
+    });
+    expect(result.current.uploading).toBe(false);
+  });
+
+  it("tracks each save separately, so one finishing does not free another", async () => {
+    // The bug this exists for: `savingPath` was a single string. Starting a
+    // second save overwrote it, so the first row went live again mid-transfer,
+    // and whichever save settled first cleared the flag for both — dismissing
+    // the second dialog was enough. A set is what the design needs, because
+    // "only the row being saved is disabled" is exactly what makes a second
+    // save startable.
+    let releaseBig: (v: unknown) => void = () => {};
+    let releaseSmall: (v: unknown) => void = () => {};
+    downloadContainerFile
+      .mockReturnValueOnce(new Promise((r) => { releaseBig = r; }))
+      .mockReturnValueOnce(new Promise((r) => { releaseSmall = r; }));
+
+    const { result } = renderHook(() => useFileManager("p1"));
+    let big: Promise<void>;
+    let small: Promise<void>;
+    act(() => { big = result.current.saveToHost(file("big.bin")); });
+    expect(result.current.savingPaths.has("/workspace/big.bin")).toBe(true);
+
+    act(() => { small = result.current.saveToHost(file("notes.txt")); });
+    // Both, at once — a scalar could only hold the second.
+    expect(result.current.savingPaths.has("/workspace/big.bin")).toBe(true);
+    expect(result.current.savingPaths.has("/workspace/notes.txt")).toBe(true);
+
+    // The second one finishing must not re-enable the first, which is still
+    // streaming. `null` is the dismissal path, which is how this was cheapest
+    // to trigger in practice.
+    await act(async () => { releaseSmall(null); await small; });
+    expect(result.current.savingPaths.has("/workspace/notes.txt")).toBe(false);
+    expect(result.current.savingPaths.has("/workspace/big.bin")).toBe(true);
+
+    await act(async () => { releaseBig(10); await big; });
+    expect(result.current.savingPaths.size).toBe(0);
+  });
+
+  it("clears a row's saving flag when its save fails", async () => {
+    downloadContainerFile.mockRejectedValueOnce("Permission denied");
+    const { result } = renderHook(() => useFileManager("p1"));
+    await act(async () => {
+      await result.current.saveToHost(file("b.txt"));
+    });
+    expect(result.current.savingPaths.size).toBe(0);
+  });
+});

app/src/hooks/useFileManager.ts

@@ -3,6 +3,7 @@ import type { FileEntry } from "../lib/types";
 import * as commands from "../lib/tauri-commands";
 import { useAppState } from "../store/appState";
 import { errorText, readableRefusal } from "../lib/refusalText";
+import { formatBytes } from "../lib/formatBytes";
 
 /**
  * ## Where failures are reported
@@ -13,8 +14,8 @@ import { errorText, readableRefusal } from "../lib/refusalText";
  * (empty) grid. It is on screen, it is in context, it explains why there are
  * no rows, and it is not transient — it stands until the directory lists.
  *
- * Every **transient operation** failure — rename, create folder — goes to
- * `ToastHost` instead. Those used to land in the same inline `error` div, which
+ * Every **transient operation** failure — rename, create folder, upload, save
+ * to host — goes to `ToastHost` instead. Those used to land in the same inline `error` div, which
  * is the first child of the *scrolling* list: three hundred rows down, a
  * refused rename produced no visible change at all, just a rename box that
  * stayed open for no stated reason. The toast host is a persistent `aria-live`
@@ -42,6 +43,28 @@ export function useFileManager(projectId: string) {
    * change a sighted user sees in the grid and a screen reader user does not.
    */
   const [completed, setCompleted] = useState<string | null>(null);
+  /**
+   * Which host transfers are in flight.
+   *
+   * Both actions open an OS dialog and can then run for a long time on a large
+   * file, with nothing on screen to say so. Without this the buttons stay live:
+   * a second click opens a second dialog and runs a second concurrent exec
+   * against the same file, and a multi-gigabyte save is indistinguishable from
+   * a click that did nothing.
+   *
+   * `savingPaths` is a **set**, not one path. Keeping only the row being
+   * disabled is what makes the pane usable during a big transfer — and that is
+   * precisely what makes a *second* save startable, so the state has to be able
+   * to hold two. As a scalar it could not: starting a save on `notes.txt` while
+   * `big.bin` was still streaming overwrote it, so `big.bin`'s button went live
+   * again mid-transfer; and whichever save finished first cleared the flag for
+   * both. Dismissing the second dialog was enough to do it.
+   *
+   * Paths are unique within a listing, so a path is a usable key — `FilesTab`
+   * relies on the same fact for its row keys.
+   */
+  const [uploading, setUploading] = useState(false);
+  const [savingPaths, setSavingPaths] = useState<ReadonlySet<string>>(new Set());
 
   const currentPathRef = useRef(currentPath);
 
@@ -154,6 +177,86 @@ export function useFileManager(projectId: string) {
     [projectId, navigate, report],
   );
 
+  /**
+   * Copy host files into the directory on screen.
+   *
+   * The picker is opened by **Rust**, not here — `upload_files_to_container`
+   * shows it, reads what the user chose and never lets a host path near IPC.
+   * So this passes a directory and gets back an outcome; `null` means the user
+   * dismissed the dialog, which is not a failure and says nothing.
+   *
+   * One dialog can select several files and they need not agree, hence two
+   * lists. Every failure is reported, because "3 of 5 uploaded" without saying
+   * which two is not a report. The listing is refreshed once, at the end, and
+   * only if the user is still looking at the directory that was targeted.
+   */
+  const uploadFiles = useCallback(async () => {
+    const target = currentPathRef.current;
+    setUploading(true);
+    try {
+      let outcome;
+      try {
+        outcome = await commands.uploadFilesToContainer(projectId, target);
+      } catch (e) {
+        // A failure *before* the picker: no container, not running, or a
+        // directory this pane may not write to. One toast, not one per file.
+        report("Could not upload", e);
+        return;
+      }
+      if (!outcome) return;
+      for (const failure of outcome.failures) {
+        useAppState.getState().pushToast({ kind: "error", message: failure });
+      }
+      if (outcome.uploaded.length === 0) return;
+      // The directory is named, not implied. `target` is captured at click time
+      // and the picker is a modal OS dialog — the user has all the time in the
+      // world to browse somewhere else while it is open, and the files land
+      // where they started. "Uploaded 2 files." in front of a grid that does
+      // not contain them is a worse answer than no message at all.
+      const count = outcome.uploaded.length;
+      setCompleted(
+        `Uploaded ${count === 1 ? "1 file" : `${count} files`} to ${target}.`,
+      );
+      if (currentPathRef.current === target) await navigate(target);
+    } finally {
+      // Around the *whole* body, refresh included. Clearing it the moment the
+      // command settled put the button back before the re-listing had run, so
+      // a second click landed mid-refresh on a grid that was still the old one.
+      setUploading(false);
+    }
+  }, [projectId, navigate, report]);
+
+  /**
+   * Save one file out to the host, with Rust opening the save dialog.
+   *
+   * No refresh: nothing in the container changed. The save dialog is also what
+   * asks about overwriting an existing host file, which is why the backend has
+   * no collision handling of its own to get wrong. `null` is a dismissal.
+   */
+  const saveToHost = useCallback(
+    async (entry: FileEntry) => {
+      setSavingPaths((live) => new Set(live).add(entry.path));
+      try {
+        const bytes = await commands.downloadContainerFile(projectId, entry.path);
+        // `0` is a real answer — an empty file saved is a success — so this
+        // tests for the dismissal sentinel, not for falsiness.
+        if (bytes === null) return;
+        setCompleted(`Saved "${entry.name}" (${formatBytes(bytes)}).`);
+      } catch (e) {
+        report(`Could not save "${entry.name}"`, e);
+      } finally {
+        // Remove only this one. A save that finishes while another is still
+        // streaming must not re-enable the other's row.
+        setSavingPaths((live) => {
+          const next = new Set(live);
+          next.delete(entry.path);
+          return next;
+        });
+      }
+    },
+    [projectId, report],
+  );
+
   return {
     currentPath,
     entries,
@@ -168,5 +271,10 @@ export function useFileManager(projectId: string) {
     refresh,
     renameEntry,
     createFolder,
+    uploadFiles,
+    saveToHost,
+    /** A host transfer is in flight — see the state declarations above. */
+    uploading,
+    savingPaths,
   };
 }

app/src/hooks/useProjectActions.ts

@@ -3,6 +3,7 @@ import { save } from "@tauri-apps/plugin-dialog";
 import type { Project } from "../lib/types";
 import * as commands from "../lib/tauri-commands";
 import { formatBytes } from "../lib/formatBytes";
+import { describeResetLeftovers, resetLeftoverPronoun } from "../lib/resetOutcome";
 import { useAppState } from "../store/appState";
 import { useProjects } from "./useProjects";
 import { useTerminal } from "./useTerminal";
@@ -28,13 +29,14 @@ export function useProjectActions(project: Project) {
   );
 
   const run = useCallback(
-    async (label: string, fn: () => Promise<unknown>) => {
+    async <T,>(label: string, fn: () => Promise<T>): Promise<T | undefined> => {
       setBusy(true);
       setContainerProgress(project.id, null);
       try {
-        await fn();
+        return await fn();
       } catch (e) {
         fail(`${label} failed for “${project.name}”`, e);
+        return undefined;
       } finally {
         setContainerProgress(project.id, null);
         setBusy(false);
@@ -54,8 +56,25 @@ export function useProjectActions(project: Project) {
   );
 
   const handleReset = useCallback(
-    () => run("Reset", () => rebuild(project.id)),
-    [run, rebuild, project.id],
+    () =>
+      run("Reset", async () => {
+        const outcome = await rebuild(project.id);
+        if (outcome.leftover_image || outcome.leftover_volumes.length > 0) {
+          // Not "run `docker volume rm`" — by the time this renders, the new
+          // container this same call just started already has the leftover
+          // volume mounted, so that command would just hit the same 409
+          // Reset did. Stopping the project first is what actually frees it.
+          pushToast({
+            kind: "error",
+            message: `Reset for “${project.name}” did not fully clean up`,
+            detail: `Triple-C could not remove ${describeResetLeftovers(outcome)} from before the reset, so \
+the new container may still be built from, or contain, old data. Stop the project, then try \
+Reset again, or remove ${resetLeftoverPronoun(outcome)} manually once stopped.`,
+          });
+        }
+        return outcome;
+      }),
+    [run, rebuild, project.id, project.name, pushToast],
   );
 
   const openClaudeTerminal = useCallback(async () => {

app/src/hooks/useProjects.test.ts

@@ -140,3 +140,27 @@ describe("useProjects puts the status back when a refused command never ran", ()
     expect(statusOf()).toBe("stopped");
   });
 });
+
+describe("useProjects.rebuild on success", () => {
+  it("puts the outcome's project, not the whole outcome, into the list", async () => {
+    const rebuilt = project("running");
+    rebuildProjectContainer.mockResolvedValue({
+      project: rebuilt,
+      leftover_image: null,
+      leftover_volumes: [],
+    });
+
+    const { result } = renderHook(() => useProjects());
+    let outcome!: Awaited<ReturnType<typeof result.current.rebuild>>;
+    await act(async () => {
+      outcome = await result.current.rebuild("p1");
+    });
+
+    // A regression here would put the `{ project, leftover_image,
+    // leftover_volumes }` wrapper into the projects list instead of the
+    // `Project` it wraps — a shape mismatch `tsc` would not catch inside a
+    // callback typed to take `unknown` per Tauri's `invoke`.
+    expect(useAppState.getState().projects.find((p) => p.id === "p1")).toEqual(rebuilt);
+    expect(outcome.leftover_volumes).toEqual([]);
+  });
+});

app/src/hooks/useProjects.ts

@@ -44,8 +44,9 @@ export function useProjects() {
 
   const remove = useCallback(
     async (id: string) => {
-      await commands.removeProject(id);
+      const report = await commands.removeProject(id);
       removeProjectFromList(id);
+      return report;
     },
     [removeProjectFromList],
   );
@@ -135,9 +136,9 @@ export function useProjects() {
   const rebuild = useCallback(
     (id: string) =>
       withOptimisticStatus(id, "starting", async () => {
-        const updated = await commands.rebuildProjectContainer(id);
-        updateProjectInList(updated);
-        return updated;
+        const outcome = await commands.rebuildProjectContainer(id);
+        updateProjectInList(outcome.project);
+        return outcome;
       }),
     [updateProjectInList, withOptimisticStatus],
   );

app/src/hooks/useSettings.ts

@@ -36,5 +36,9 @@ export function useSettings() {
     appSettings,
     loadSettings,
     saveSettings,
+    /** For a command that already returns the new `AppSettings` itself
+     *  (settings import) — updates the store without a redundant
+     *  `updateSettings` round trip through the backend. */
+    setAppSettings,
   };
 }

app/src/hooks/useTerminal.test.ts

@@ -0,0 +1,83 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+// The queue lives at module scope in useTerminal, so the command layer is
+// mocked and the hook's `sendInput` is exercised through `renderHook`.
+const terminalInput = vi.fn<(sessionId: string, data: number[]) => Promise<void>>();
+
+vi.mock("../lib/tauri-commands", () => ({
+  terminalInput: (sessionId: string, data: number[]) => terminalInput(sessionId, data),
+  openTerminalSession: vi.fn(),
+  closeTerminalSession: vi.fn(),
+  terminalResize: vi.fn(),
+  pasteImageToTerminal: vi.fn(),
+  updateProject: vi.fn(),
+}));
+
+vi.mock("@tauri-apps/api/event", () => ({ listen: vi.fn() }));
+
+import { renderHook } from "@testing-library/react";
+import { useTerminal } from "./useTerminal";
+
+const decode = (bytes: number[]) => new TextDecoder().decode(new Uint8Array(bytes));
+
+describe("useTerminal input ordering", () => {
+  beforeEach(() => {
+    terminalInput.mockReset();
+  });
+
+  it("preserves order even when the underlying invokes resolve out of order", async () => {
+    // Make the *first* call the slowest, which is exactly the race that put a
+    // backspace behind the characters typed after it.
+    const resolvers: Array<() => void> = [];
+    terminalInput.mockImplementation(
+      () => new Promise<void>((resolve) => resolvers.push(resolve)),
+    );
+
+    const { result } = renderHook(() => useTerminal());
+
+    const first = result.current.sendInput("s1", "\x7f"); // backspace
+    const rest = ["a", "b", "c"].map((ch) => result.current.sendInput("s1", ch));
+
+    // Only one write may be in flight at a time.
+    expect(terminalInput).toHaveBeenCalledTimes(1);
+    expect(decode(terminalInput.mock.calls[0][1])).toBe("\x7f");
+
+    resolvers.shift()!();
+    await first;
+
+    // The three queued keystrokes coalesce into one ordered write.
+    expect(terminalInput).toHaveBeenCalledTimes(2);
+    expect(decode(terminalInput.mock.calls[1][1])).toBe("abc");
+
+    resolvers.shift()!();
+    await Promise.all(rest);
+
+    const sent = terminalInput.mock.calls.map((c) => decode(c[1])).join("");
+    expect(sent).toBe("\x7fabc");
+  });
+
+  it("settles each caller's promise and does not drop later writes on failure", async () => {
+    terminalInput.mockRejectedValueOnce(new Error("boom")).mockResolvedValue(undefined);
+
+    const { result } = renderHook(() => useTerminal());
+
+    await expect(result.current.sendInput("s2", "x")).rejects.toThrow("boom");
+    await expect(result.current.sendInput("s2", "y")).resolves.toBeUndefined();
+
+    expect(decode(terminalInput.mock.calls[1][1])).toBe("y");
+  });
+
+  it("keeps separate sessions independent", async () => {
+    terminalInput.mockResolvedValue(undefined);
+    const { result } = renderHook(() => useTerminal());
+
+    await Promise.all([
+      result.current.sendInput("a", "1"),
+      result.current.sendInput("b", "2"),
+    ]);
+
+    const bySession = terminalInput.mock.calls.map((c) => [c[0], decode(c[1])]);
+    expect(bySession).toContainEqual(["a", "1"]);
+    expect(bySession).toContainEqual(["b", "2"]);
+  });
+});

app/src/hooks/useTerminal.ts

@@ -4,6 +4,86 @@ import { listen } from "@tauri-apps/api/event";
 import { useAppState } from "../store/appState";
 import * as commands from "../lib/tauri-commands";
 
+/**
+ * Per-session ordered write queue.
+ *
+ * Every keystroke used to be its own `invoke("terminal_input")`, and because
+ * that command is `async` on the Rust side Tauri spawns each one as an
+ * independent task. Those tasks then race for the session mutex in
+ * `ExecSessionManager::send_input`, so nothing preserved the order the bytes
+ * were typed in — the visible symptom was a backspace landing *after* the
+ * characters typed behind it. The serial writer task downstream cannot help,
+ * because the order is already lost by the time anything reaches the channel.
+ *
+ * The queue restores ordering the same way the web terminal gets it for free:
+ * one write in flight at a time, the next only after the previous resolves.
+ * Anything typed while a write is in flight coalesces into the next chunk,
+ * which also collapses a burst of typing into a couple of IPC round trips
+ * rather than one per key. Concatenating the byte arrays is safe — a PTY
+ * cannot tell one write of "ab" from writes of "a" then "b" — and each
+ * caller's promise still settles only when its own bytes have gone, so
+ * `await sendInput(...)` keeps the meaning it had.
+ *
+ * Module scope, not hook scope, because `useTerminal()` is called from several
+ * components (App for speech-to-text, TerminalView for typing and image paste,
+ * useProjectActions for tile commands). A per-hook queue would give each caller
+ * its own ordering and leave them racing against each other.
+ */
+type PendingWrite = {
+  bytes: number[];
+  resolve: () => void;
+  reject: (reason: unknown) => void;
+};
+
+const inputQueues = new Map<string, { pending: PendingWrite[]; draining: boolean }>();
+
+async function drainInputQueue(sessionId: string): Promise<void> {
+  const q = inputQueues.get(sessionId);
+  if (!q || q.draining) return;
+
+  q.draining = true;
+  try {
+    while (q.pending.length > 0) {
+      // Take everything queued so far as one batch, preserving order.
+      const batch = q.pending.splice(0, q.pending.length);
+      const bytes = batch.flatMap((w) => w.bytes);
+      try {
+        await commands.terminalInput(sessionId, bytes);
+        batch.forEach((w) => w.resolve());
+      } catch (err) {
+        // Reject only the writes in this batch. Anything queued while it was
+        // in flight is still pending and gets its own attempt on the next lap.
+        batch.forEach((w) => w.reject(err));
+      }
+    }
+  } finally {
+    q.draining = false;
+    // Drop the entry once idle so closed sessions do not accumulate.
+    if (q.pending.length === 0) inputQueues.delete(sessionId);
+  }
+}
+
+function enqueueInput(sessionId: string, bytes: number[]): Promise<void> {
+  return new Promise<void>((resolve, reject) => {
+    let q = inputQueues.get(sessionId);
+    if (!q) {
+      q = { pending: [], draining: false };
+      inputQueues.set(sessionId, q);
+    }
+    q.pending.push({ bytes, resolve, reject });
+    void drainInputQueue(sessionId);
+  });
+}
+
+/** Drop any queued input for a session that is going away. */
+function discardInputQueue(sessionId: string): void {
+  const q = inputQueues.get(sessionId);
+  if (!q) return;
+  const dropped = q.pending.splice(0, q.pending.length);
+  dropped.forEach((w) => w.reject(new Error(`Session ${sessionId} closed`)));
+  if (!q.draining) inputQueues.delete(sessionId);
+}
+
 export function useTerminal() {
   const { sessions, activeSessionId, addSession, removeSession, setActiveSession } =
     useAppState(
@@ -33,6 +113,7 @@ export function useTerminal() {
       const session = currentSessions.find((s) => s.id === sessionId);
       const project = session ? projects.find((p) => p.id === session.projectId) : undefined;
 
+      discardInputQueue(sessionId);
       await commands.closeTerminalSession(sessionId);
       removeSession(sessionId);
 
@@ -54,7 +135,7 @@ export function useTerminal() {
   const sendInput = useCallback(
     async (sessionId: string, data: string) => {
       const bytes = Array.from(new TextEncoder().encode(data));
-      await commands.terminalInput(sessionId, bytes);
+      await enqueueInput(sessionId, bytes);
     },
     [],
   );

app/src/lib/dropTarget.ts

@@ -9,8 +9,9 @@
  *    payload position inside my rect? A hidden pane is `display:none` and so
  *    has a zero-size rect, which is what stops two panes both claiming the
  *    same drop. `TerminalView` is the only pane that takes dropped files
- *    today — the Files pane is container-side only — but the routing is what
- *    keeps it honest when a second one appears.
+ *    today — the Files pane copies files through buttons and a backend-opened
+ *    dialog, not through a drop — but the routing is what keeps it honest when
+ *    a second one appears.
  * 2. **Should the app accept a drop at all right now?** `dropIsBlocked` —
  *    document-wide, no geometry, no z-order. While a modal or a blocking
  *    overlay is on screen anywhere, every drop is refused.

app/src/lib/resetOutcome.test.ts

@@ -0,0 +1,39 @@
+import { describe, it, expect } from "vitest";
+import { describeResetLeftovers, resetLeftoverPronoun } from "./resetOutcome";
+import type { ProjectResetOutcome } from "./types";
+
+function outcome(overrides: Partial<ProjectResetOutcome> = {}): ProjectResetOutcome {
+  return {
+    project: {} as ProjectResetOutcome["project"],
+    leftover_image: null,
+    leftover_volumes: [],
+    ...overrides,
+  };
+}
+
+describe("describeResetLeftovers", () => {
+  it("names the image first, then the volumes", () => {
+    expect(describeResetLeftovers(outcome({ leftover_image: "x" }))).toBe(
+      "its previous container image",
+    );
+    expect(describeResetLeftovers(outcome({ leftover_volumes: ["v1"] }))).toBe("a volume");
+    expect(describeResetLeftovers(outcome({ leftover_volumes: ["v1", "v2"] }))).toBe("2 volumes");
+    expect(
+      describeResetLeftovers(outcome({ leftover_image: "x", leftover_volumes: ["v1", "v2"] })),
+    ).toBe("its previous container image and 2 volumes");
+  });
+});
+
+describe("resetLeftoverPronoun", () => {
+  it("is singular for exactly one leftover", () => {
+    expect(resetLeftoverPronoun(outcome({ leftover_image: "x" }))).toBe("it");
+    expect(resetLeftoverPronoun(outcome({ leftover_volumes: ["v1"] }))).toBe("it");
+  });
+
+  it("is plural once more than one thing survived", () => {
+    expect(resetLeftoverPronoun(outcome({ leftover_image: "x", leftover_volumes: ["v1"] }))).toBe(
+      "them",
+    );
+    expect(resetLeftoverPronoun(outcome({ leftover_volumes: ["v1", "v2"] }))).toBe("them");
+  });
+});

app/src/lib/resetOutcome.ts

@@ -0,0 +1,32 @@
+import type { ProjectResetOutcome } from "./types";
+
+/**
+ * Names what a `ProjectResetOutcome` says Reset could not clear, for
+ * `useProjectActions`'s Reset toast.
+ *
+ * The image is named first and phrased as "its previous container image"
+ * rather than folded in with the volumes — it is the more serious of the
+ * two: the new container is built from it whenever it exists, so a
+ * surviving image means Reset silently rebuilt the exact system layer it
+ * was asked to discard, while a surviving volume only means old data rides
+ * along.
+ */
+export function describeResetLeftovers(outcome: ProjectResetOutcome): string {
+  const parts: string[] = [];
+  if (outcome.leftover_image) parts.push("its previous container image");
+  if (outcome.leftover_volumes.length === 1) parts.push("a volume");
+  else if (outcome.leftover_volumes.length > 1) parts.push(`${outcome.leftover_volumes.length} volumes`);
+  return parts.join(" and ");
+}
+
+/** How many distinct things `describeResetLeftovers` is describing — the
+ *  image counts as one, however many volumes are named alongside it. */
+function resetLeftoverCount(outcome: ProjectResetOutcome): number {
+  return (outcome.leftover_image ? 1 : 0) + outcome.leftover_volumes.length;
+}
+
+/** Pronoun agreement for referring back to `describeResetLeftovers`'s
+ *  output — "remove it manually" for one thing, "remove them" for more. */
+export function resetLeftoverPronoun(outcome: ProjectResetOutcome): "it" | "them" {
+  return resetLeftoverCount(outcome) === 1 ? "it" : "them";
+}

app/src/lib/settingsImportPreview.test.ts

@@ -0,0 +1,125 @@
+import { describe, it, expect } from "vitest";
+import { describeImport, describeImportWarnings } from "./settingsImportPreview";
+import type { SettingsImportPreview } from "./types";
+
+function preview(overrides: Partial<SettingsImportPreview> = {}): SettingsImportPreview {
+  return {
+    exported_at: "2026-08-27T00:00:00Z",
+    app_version: "0.4.14",
+    custom_env_var_count: 0,
+    gateway_model_count: 0,
+    has_claude_code_settings: false,
+    has_claude_oauth_token: false,
+    has_gateway_api_key: false,
+    has_gateway_master_key: false,
+    has_web_terminal_access_token: false,
+    enables_web_terminal: false,
+    ollama_base_url: null,
+    llamacpp_base_url: null,
+    openai_compatible_base_url: null,
+    gateway_api_base: null,
+    image_source: "registry",
+    custom_image_name: null,
+    ...overrides,
+  };
+}
+
+describe("describeImport", () => {
+  it("always names the settings replacement, even with nothing else set", () => {
+    expect(describeImport(preview())).toEqual([
+      "Your global settings (all of them — this replaces what's here now)",
+    ]);
+  });
+
+  it("singularizes a count of exactly one", () => {
+    const items = describeImport(preview({ custom_env_var_count: 1, gateway_model_count: 1 }));
+    expect(items).toContain("1 global custom env var");
+    expect(items).toContain("1 gateway model");
+  });
+
+  it("pluralizes counts greater than one", () => {
+    const items = describeImport(preview({ custom_env_var_count: 3, gateway_model_count: 2 }));
+    expect(items).toContain("3 global custom env vars");
+    expect(items).toContain("2 gateway models");
+  });
+
+  it("names every present secret and setting without naming absent ones", () => {
+    const items = describeImport(
+      preview({
+        has_claude_code_settings: true,
+        has_claude_oauth_token: true,
+        has_gateway_api_key: true,
+        has_gateway_master_key: true,
+      }),
+    );
+    expect(items).toContain("Global Claude Code settings");
+    expect(items).toContain("Your shared Claude login");
+    expect(items).toContain("The gateway provider API key");
+    expect(items).toContain("The gateway master key");
+    // None of the count-based items, since both counts are 0.
+    expect(items.some((i) => i.includes("env var"))).toBe(false);
+    expect(items.some((i) => i.includes("gateway model"))).toBe(false);
+  });
+
+  it("names the web terminal access token like any other present secret", () => {
+    const items = describeImport(preview({ has_web_terminal_access_token: true }));
+    expect(items).toContain("The web terminal access token");
+  });
+
+  it("names custom base URLs verbatim, since they're endpoints rather than secrets", () => {
+    const items = describeImport(
+      preview({
+        ollama_base_url: "http://10.0.0.5:11434",
+        gateway_api_base: "https://gateway.example/v1",
+      }),
+    );
+    expect(items).toContain("Ollama server: http://10.0.0.5:11434");
+    expect(items).toContain("Gateway upstream: https://gateway.example/v1");
+    expect(items.some((i) => i.includes("llama.cpp"))).toBe(false);
+    expect(items.some((i) => i.includes("OpenAI-compatible"))).toBe(false);
+  });
+
+  it("names a custom Docker image when set, falling back to a placeholder if unnamed", () => {
+    expect(
+      describeImport(preview({ image_source: "custom", custom_image_name: "ghcr.io/me/triple-c" })),
+    ).toContain("Docker image: ghcr.io/me/triple-c");
+    expect(describeImport(preview({ image_source: "custom", custom_image_name: null }))).toContain(
+      "Docker image: (no image name set)",
+    );
+    expect(describeImport(preview({ image_source: "registry" })).some((i) => i.includes("Docker image"))).toBe(
+      false,
+    );
+  });
+});
+
+describe("describeImportWarnings", () => {
+  it("is empty when nothing about the import needs extra attention", () => {
+    expect(describeImportWarnings(preview())).toEqual([]);
+  });
+
+  it("warns when the import enables the web terminal, regardless of the token", () => {
+    // `enabled` and the token are independent — the warning is about the
+    // service turning on, whether or not a token came with it.
+    expect(describeImportWarnings(preview({ enables_web_terminal: true }))).toEqual([
+      "Enables the remote web terminal, which listens on your network.",
+    ]);
+    expect(
+      describeImportWarnings(
+        preview({ enables_web_terminal: true, has_web_terminal_access_token: true }),
+      ),
+    ).toHaveLength(1);
+  });
+
+  it("warns about a dormant web terminal token even while the terminal stays off", () => {
+    expect(describeImportWarnings(preview({ has_web_terminal_access_token: true }))).toEqual([
+      "Includes a web terminal access token that will activate the next time the web terminal is turned on.",
+    ]);
+  });
+
+  it("warns about a custom Docker image every time, not only when it changes", () => {
+    expect(
+      describeImportWarnings(preview({ image_source: "custom", custom_image_name: "evil:latest" })),
+    ).toEqual(["Runs every project container from a custom Docker image: evil:latest."]);
+    expect(describeImportWarnings(preview({ image_source: "registry" }))).toEqual([]);
+  });
+});

app/src/lib/settingsImportPreview.ts

@@ -0,0 +1,67 @@
+import type { SettingsImportPreview } from "./types";
+
+/** Named things a `SettingsImportPreview` says an import will change, for
+ *  `ImportSettingsModal`'s confirmation list. Does not include anything
+ *  `describeImportWarnings` covers — those get their own, more visible
+ *  treatment rather than blending into this list. */
+export function describeImport(preview: SettingsImportPreview): string[] {
+  const items: string[] = ["Your global settings (all of them — this replaces what's here now)"];
+  if (preview.custom_env_var_count > 0) {
+    items.push(
+      `${preview.custom_env_var_count} global custom env var${preview.custom_env_var_count === 1 ? "" : "s"}`,
+    );
+  }
+  if (preview.has_claude_code_settings) items.push("Global Claude Code settings");
+  if (preview.gateway_model_count > 0) {
+    items.push(`${preview.gateway_model_count} gateway model${preview.gateway_model_count === 1 ? "" : "s"}`);
+  }
+  if (preview.has_claude_oauth_token) items.push("Your shared Claude login");
+  if (preview.has_gateway_api_key) items.push("The gateway provider API key");
+  if (preview.has_gateway_master_key) items.push("The gateway master key");
+  if (preview.has_web_terminal_access_token) items.push("The web terminal access token");
+  if (preview.ollama_base_url) items.push(`Ollama server: ${preview.ollama_base_url}`);
+  if (preview.llamacpp_base_url) items.push(`llama.cpp server: ${preview.llamacpp_base_url}`);
+  if (preview.openai_compatible_base_url) {
+    items.push(`OpenAI-compatible server: ${preview.openai_compatible_base_url}`);
+  }
+  if (preview.gateway_api_base) items.push(`Gateway upstream: ${preview.gateway_api_base}`);
+  if (preview.image_source === "custom") {
+    items.push(`Docker image: ${preview.custom_image_name ?? "(no image name set)"}`);
+  }
+  return items;
+}
+
+/**
+ * Things about an import that deserve more attention than a bullet in a
+ * long list — deliberately its own function rather than a flag inside
+ * `describeImport`: a setting that turns on a network-listening service is
+ * exactly the kind of change a "your settings were replaced" summary is bad
+ * at surfacing, on purpose or (if the file came from someone else) not.
+ *
+ * A token that arrives with the terminal left *off* gets its own warning
+ * too, distinct from the "enables it now" one: `start_web_terminal` only
+ * mints a fresh token when none is already set, so a planted token here
+ * would silently become live the next time someone flips the terminal on
+ * through the UI, with no import-time signal that it wasn't freshly
+ * generated.
+ *
+ * A custom Docker image gets a warning every time, not just on change: it's
+ * the image every project container is created from, so it's worth calling
+ * out regardless of what was configured before the import.
+ */
+export function describeImportWarnings(preview: SettingsImportPreview): string[] {
+  const warnings: string[] = [];
+  if (preview.enables_web_terminal) {
+    warnings.push("Enables the remote web terminal, which listens on your network.");
+  } else if (preview.has_web_terminal_access_token) {
+    warnings.push(
+      "Includes a web terminal access token that will activate the next time the web terminal is turned on.",
+    );
+  }
+  if (preview.image_source === "custom") {
+    warnings.push(
+      `Runs every project container from a custom Docker image: ${preview.custom_image_name ?? "(no image name set)"}.`,
+    );
+  }
+  return warnings;
+}

app/src/lib/tauri-commands.ts

@@ -1,5 +1,5 @@
 import { invoke } from "@tauri-apps/api/core";
-import type { Project, ProjectPath, ContainerInfo, AppSettings, UpdateInfo, ImageUpdateInfo, FileEntry, FileContents, WebTerminalInfo, SttStatus, GatewayStatus, InstallOptions, ClaudeSession, ContainerCapabilities, ScheduledTask, ScheduledTaskInput, SchedulerNotification, AuthBridgeStatus, BrowserViewStatus, BrowserViewPopoutState, BrowserPageState, PlaywrightDetection, BrowserSetupOutcome, BrowserInstallTarget, ContainerStaleness, MigrationOptions, MigrationReport, MigrationState, ClearTokenOutcome, CaCertInfo } from "./types";
+import type { Project, ProjectPath, ProjectRemovalReport, ProjectResetOutcome, ContainerInfo, AppSettings, SettingsImportPreview, SettingsImportOutcome, UpdateInfo, ImageUpdateInfo, FileEntry, FileContents, WebTerminalInfo, SttStatus, GatewayStatus, InstallOptions, ClaudeSession, ContainerCapabilities, ScheduledTask, ScheduledTaskInput, SchedulerNotification, AuthBridgeStatus, BrowserViewStatus, BrowserViewPopoutState, BrowserPageState, PlaywrightDetection, BrowserSetupOutcome, BrowserInstallTarget, ContainerStaleness, MigrationOptions, MigrationReport, MigrationState, ClearTokenOutcome, CaCertInfo, UploadOutcome } from "./types";
 
 // Docker
 export const checkDocker = () => invoke<boolean>("check_docker");
@@ -13,7 +13,7 @@ export const listProjects = () => invoke<Project[]>("list_projects");
 export const addProject = (name: string, paths: ProjectPath[]) =>
   invoke<Project>("add_project", { name, paths });
 export const removeProject = (projectId: string) =>
-  invoke<void>("remove_project", { projectId });
+  invoke<ProjectRemovalReport>("remove_project", { projectId });
 export const updateProject = (project: Project) =>
   invoke<Project>("update_project", { project });
 export const startProjectContainer = (projectId: string) =>
@@ -21,7 +21,7 @@ export const startProjectContainer = (projectId: string) =>
 export const stopProjectContainer = (projectId: string) =>
   invoke<void>("stop_project_container", { projectId });
 export const rebuildProjectContainer = (projectId: string) =>
-  invoke<Project>("rebuild_project_container", { projectId });
+  invoke<ProjectResetOutcome>("rebuild_project_container", { projectId });
 export const reconcileProjectStatuses = () =>
   invoke<Project[]>("reconcile_project_statuses");
 
@@ -42,6 +42,15 @@ export const inspectCaCertPath = (path: string) =>
 export const detectHostTimezone = () =>
   invoke<string>("detect_host_timezone");
 
+// Settings export/import — `false`/`null` mean the save/open dialog was
+// dismissed, not an error.
+export const exportSettings = (password: string) =>
+  invoke<boolean>("export_settings", { password });
+export const previewSettingsImport = (password: string) =>
+  invoke<SettingsImportPreview | null>("preview_settings_import", { password });
+export const applySettingsImport = (password: string) =>
+  invoke<SettingsImportOutcome>("apply_settings_import", { password });
+
 // AWS
 export const awsSsoRefresh = (projectId: string) =>
   invoke<void>("aws_sso_refresh", { projectId });
@@ -69,6 +78,25 @@ export const stopAudioBridge = (sessionId: string) =>
 // Files
 export const listContainerFiles = (projectId: string, path: string) =>
   invoke<FileEntry[]>("list_container_files", { projectId, path });
+/**
+ * Save one container file to the host.
+ *
+ * The **backend** opens the save dialog, so this call cannot name a place on
+ * the host — that is the point (see `pick_save_path` in `file_commands.rs`).
+ * Paths do come *back* inside error text; what is closed is the inbound
+ * direction.
+ * Resolves to the number of bytes written, or `null` if the user dismissed the
+ * dialog. Zero bytes is a success: an empty file is a file.
+ */
+export const downloadContainerFile = (projectId: string, containerPath: string) =>
+  invoke<number | null>("download_container_file", { projectId, containerPath });
+/**
+ * Upload host files into `containerDir`, with the backend opening the file
+ * picker. Resolves to `null` if the user dismissed it, otherwise to what
+ * happened — one dialog can select several files and they need not all succeed.
+ */
+export const uploadFilesToContainer = (projectId: string, containerDir: string) =>
+  invoke<UploadOutcome | null>("upload_files_to_container", { projectId, containerDir });
 export const downloadContainerBackup = (projectId: string, hostPath: string, containerPath?: string) =>
   invoke<number>("download_container_backup", { projectId, hostPath, containerPath });
 export const readContainerFile = (projectId: string, path: string, maxBytes?: number) =>

app/src/lib/terminalRenderer.test.ts

@@ -0,0 +1,39 @@
+import { describe, it, expect } from "vitest";
+import { isLinuxWebview, resolveTerminalGpuRendering } from "./terminalRenderer";
+
+const LINUX = "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/605.1.15 Safari/605.1.15";
+const MAC = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 Safari/605.1.15";
+const WINDOWS = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/120 Safari/537.36";
+const ANDROID = "Mozilla/5.0 (Linux; Android 14) AppleWebKit/537.36 Chrome/120 Mobile Safari/537.36";
+
+describe("isLinuxWebview", () => {
+  it("recognises desktop Linux", () => {
+    expect(isLinuxWebview(LINUX)).toBe(true);
+  });
+
+  it("does not count Android as desktop Linux", () => {
+    expect(isLinuxWebview(ANDROID)).toBe(false);
+  });
+
+  it("rejects the other desktop platforms", () => {
+    expect(isLinuxWebview(MAC)).toBe(false);
+    expect(isLinuxWebview(WINDOWS)).toBe(false);
+  });
+});
+
+describe("resolveTerminalGpuRendering", () => {
+  it("auto is off on Linux, where WebGL falls back to software rendering", () => {
+    expect(resolveTerminalGpuRendering(null, LINUX)).toBe(false);
+    expect(resolveTerminalGpuRendering(undefined, LINUX)).toBe(false);
+  });
+
+  it("auto is on elsewhere", () => {
+    expect(resolveTerminalGpuRendering(null, MAC)).toBe(true);
+    expect(resolveTerminalGpuRendering(null, WINDOWS)).toBe(true);
+  });
+
+  it("an explicit setting wins on every platform", () => {
+    expect(resolveTerminalGpuRendering(true, LINUX)).toBe(true);
+    expect(resolveTerminalGpuRendering(false, MAC)).toBe(false);
+  });
+});

app/src/lib/terminalRenderer.ts

@@ -0,0 +1,28 @@
+/**
+ * Decides whether the terminal loads `@xterm/addon-webgl`.
+ *
+ * Split out of `TerminalView` so it can be unit-tested without standing up a
+ * terminal, and so the platform rule lives in exactly one place.
+ */
+
+/** True when the webview is running on Linux (WebKitGTK), excluding Android. */
+export function isLinuxWebview(userAgent: string): boolean {
+  return /\bLinux\b/.test(userAgent) && !/\bAndroid\b/.test(userAgent);
+}
+
+/**
+ * Resolve the effective WebGL setting.
+ *
+ * `setting` is `AppSettings.terminal_gpu_rendering`: `true`/`false` force the
+ * answer, `null`/`undefined` mean auto. Auto is on everywhere except Linux —
+ * there the app disables WebKitGTK's DMA-BUF renderer at startup (triple-c#34),
+ * which leaves WebGL present but software-rasterised, so loading the addon is
+ * slower than the canvas renderer it would otherwise have fallen back to.
+ */
+export function resolveTerminalGpuRendering(
+  setting: boolean | null | undefined,
+  userAgent: string,
+): boolean {
+  if (typeof setting === "boolean") return setting;
+  return !isLinuxWebview(userAgent);
+}

app/src/lib/types.ts

@@ -77,6 +77,37 @@ export type ProjectStatus =
   | "stopping"
   | "error";
 
+/** What `removeProject` could not delete. The project is removed from the
+ *  sidebar either way. When `retry_scheduled` is true, anything named here
+ *  was recorded on the host and will be retried automatically the next time
+ *  the app starts; when false, the record itself could not be saved and
+ *  nothing will retry it. `retry_scheduled` is meaningless when nothing was
+ *  left behind. */
+export interface ProjectRemovalReport {
+  container: string | null;
+  image: string | null;
+  volumes: string[];
+  retry_scheduled: boolean;
+}
+
+/** True when a `ProjectRemovalReport` left nothing behind. Mirrors the
+ *  Rust-side `ProjectRemovalReport::is_clean`. */
+export function projectRemovalIsClean(report: ProjectRemovalReport): boolean {
+  return !report.container && !report.image && report.volumes.length === 0;
+}
+
+/** What Reset (`rebuildProjectContainer`) produced: the project as it stands
+ *  after restarting, and any volume Reset could not clear — which is reused
+ *  as-is by the new container instead of starting clean. */
+export interface ProjectResetOutcome {
+  project: Project;
+  /** The saved container image, if Reset could not remove it — the new
+   *  container is built from it whenever it exists, so this means Reset
+   *  silently rebuilt the system layer it was asked to discard. */
+  leftover_image: string | null;
+  leftover_volumes: string[];
+}
+
 export type Backend =
   | "anthropic"
   | "bedrock"
@@ -259,6 +290,52 @@ export interface AppSettings {
   stt: SttSettings;
   gateway: GatewaySettings;
   global_claude_code_settings: ClaudeCodeSettings | null;
+  /** Whether the terminal loads the WebGL renderer. `null` is auto: on
+   *  everywhere except Linux, where the DMA-BUF workaround leaves WebGL
+   *  backed by software rasterisation and the addon ends up slower than the
+   *  canvas renderer it would otherwise fall back to. See
+   *  `resolveTerminalGpuRendering` in `lib/terminalRenderer.ts`. */
+  terminal_gpu_rendering: boolean | null;
+}
+
+/** What `preview_settings_import` returns before anything is applied —
+ *  counts and presence flags only, never a secret value itself. Built from
+ *  this, not from the raw import file, which the frontend never sees. */
+export interface SettingsImportPreview {
+  exported_at: string;
+  app_version: string;
+  custom_env_var_count: number;
+  gateway_model_count: number;
+  has_claude_code_settings: boolean;
+  has_claude_oauth_token: boolean;
+  has_gateway_api_key: boolean;
+  has_gateway_master_key: boolean;
+  has_web_terminal_access_token: boolean;
+  /** Whether the import turns the web terminal on — surfaced separately
+   *  from the token above since either can be true without the other, and
+   *  "this enables a service that listens on your network" must not hide
+   *  inside a generic "settings replaced" summary. */
+  enables_web_terminal: boolean;
+  /** Non-blank custom base URLs the import would set — endpoints, not
+   *  secrets, so shown verbatim to disclose a redirect of model traffic. */
+  ollama_base_url: string | null;
+  llamacpp_base_url: string | null;
+  openai_compatible_base_url: string | null;
+  gateway_api_base: string | null;
+  /** Whether the import sets a custom Docker image, and its name if so —
+   *  this is the image every project container is created from, so worth
+   *  more attention than an ordinary setting. */
+  image_source: ImageSource;
+  custom_image_name: string | null;
+}
+
+/** What `apply_settings_import` returns: the settings that were actually
+ *  saved, plus a note for each keychain secret the import carried but could
+ *  not be restored (a partial keychain failure must not read as unqualified
+ *  success just because the settings half went through). */
+export interface SettingsImportOutcome {
+  settings: AppSettings;
+  secret_restore_warnings: string[];
 }
 
 /** What `inspect_ca_cert_path` reports about a corporate CA path. Errors ride
@@ -365,6 +442,22 @@ export interface FileEntry {
   permissions: string;
 }
 
+/**
+ * What one upload dialog's worth of files did — mirrors `UploadOutcome` in
+ * `commands/file_commands.rs`.
+ *
+ * Two lists rather than a count and a flag, because one dialog can select
+ * several files and they do not have to agree: a folder among the selection, or
+ * a file over the size ceiling, must not cost the user the ones either side of
+ * it. Each `failures` entry is already a finished sentence naming its file.
+ */
+export interface UploadOutcome {
+  /** In-container paths, in the order they landed. */
+  uploaded: string[];
+  /** One sentence per file that did not. */
+  failures: string[];
+}
+
 /** A file read out of the container for the in-app viewer. */
 export interface FileContents {
   /** Base64 — a byte array would cross IPC as JSON numbers. */

scripts/install-appimage.sh

@@ -0,0 +1,127 @@
+#!/bin/sh
+# Register a Triple-C AppImage with the desktop, so it appears in the app
+# launcher with its icon instead of only being runnable from a file manager.
+#
+# An AppImage is a single executable file and nothing more: it ships a
+# `.desktop` entry and icons *inside* itself, but nothing on the host ever
+# reads them, because nothing installed it. This script does what a package
+# manager's install hooks would — copies the icons into the user's icon theme
+# and writes a `.desktop` entry pointing at wherever the AppImage actually
+# lives.
+#
+#     ./scripts/install-appimage.sh ~/Apps/Triple-C_0.4.17_amd64.AppImage
+#     ./scripts/install-appimage.sh --uninstall
+#
+# Everything goes under ~/.local/share, so there is no sudo and no root-owned
+# file to clean up later. The AppImage itself is never copied or moved — the
+# launcher entry points at the path you give here, so keep the file somewhere
+# stable (`~/Apps` or `~/.local/bin`, not `~/Downloads`) or re-run this after
+# moving it.
+#
+# Extraction uses `--appimage-extract`, which unpacks the payload directly and
+# needs no FUSE. So this script works even on a system where *running* the
+# AppImage would need `fuse2` installed first.
+
+set -eu
+
+APP_ID="triple-c"
+DESKTOP_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/applications"
+ICON_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/icons/hicolor"
+DESKTOP_FILE="${DESKTOP_DIR}/${APP_ID}.desktop"
+
+refresh_caches() {
+    # Both are best-effort: a minimal desktop may ship neither, and neither
+    # failing means the install did not work.
+    if command -v update-desktop-database >/dev/null 2>&1; then
+        update-desktop-database "${DESKTOP_DIR}" 2>/dev/null || true
+    fi
+    if command -v gtk-update-icon-cache >/dev/null 2>&1; then
+        gtk-update-icon-cache -f -t "${ICON_DIR}" 2>/dev/null || true
+    fi
+}
+
+uninstall() {
+    rm -f "${DESKTOP_FILE}"
+    find "${ICON_DIR}" -name "${APP_ID}.png" -delete 2>/dev/null || true
+    refresh_caches
+    echo "Removed the Triple-C launcher entry and icons."
+    echo "The AppImage itself was not touched."
+}
+
+if [ "${1:-}" = "--uninstall" ]; then
+    uninstall
+    exit 0
+fi
+
+APPIMAGE="${1:-}"
+if [ -z "${APPIMAGE}" ]; then
+    echo "usage: $0 [--uninstall] /path/to/Triple-C_<version>_amd64.AppImage" >&2
+    exit 2
+fi
+if [ ! -f "${APPIMAGE}" ]; then
+    echo "No such file: ${APPIMAGE}" >&2
+    exit 1
+fi
+
+# An absolute path, because the .desktop Exec line is read from anywhere.
+APPIMAGE=$(cd "$(dirname "${APPIMAGE}")" && printf '%s/%s' "$(pwd)" "$(basename "${APPIMAGE}")")
+
+if [ ! -x "${APPIMAGE}" ]; then
+    echo "Making ${APPIMAGE} executable"
+    chmod +x "${APPIMAGE}"
+fi
+
+WORK=$(mktemp -d)
+# shellcheck disable=SC2064  # WORK is expanded now on purpose.
+trap "rm -rf '${WORK}'" EXIT INT TERM
+
+echo "Extracting bundled icons from $(basename "${APPIMAGE}")..."
+( cd "${WORK}" && "${APPIMAGE}" --appimage-extract >/dev/null )
+
+SRC="${WORK}/squashfs-root"
+if [ ! -d "${SRC}/usr/share/icons/hicolor" ]; then
+    echo "That AppImage has no bundled icons — is it really Triple-C?" >&2
+    exit 1
+fi
+
+# Copy every size the bundle ships, keeping the theme's directory layout.
+COUNT=0
+while IFS= read -r icon; do
+    [ -n "${icon}" ] || continue
+    rel=${icon#"${SRC}/usr/share/icons/hicolor/"}
+    install -Dm644 "${icon}" "${ICON_DIR}/${rel}"
+    COUNT=$((COUNT + 1))
+done <<EOF
+$(find "${SRC}/usr/share/icons/hicolor" -name "${APP_ID}.png")
+EOF
+echo "Installed ${COUNT} icon size(s) into ${ICON_DIR}"
+
+# Written rather than copied from the bundle. The bundled entry has
+# `Exec=triple-c`, which resolves only inside the running AppImage's own mount
+# — from the host it names a binary that is not on PATH, so the launcher entry
+# would appear and then fail to start anything. `Categories` is empty in the
+# bundle too, which leaves the entry to fall into "Other" in most menus.
+# `StartupWMClass` is kept exactly as the bundle sets it: it is what lets the
+# shell match the running window to this entry, so the taskbar shows the real
+# icon instead of a generic placeholder.
+mkdir -p "${DESKTOP_DIR}"
+cat > "${DESKTOP_FILE}" <<DESKTOP
+[Desktop Entry]
+Type=Application
+Name=Triple-C
+Comment=Run Claude Code sandboxed in Docker containers
+Exec=${APPIMAGE} %U
+Icon=${APP_ID}
+Terminal=false
+Categories=Development;
+StartupWMClass=${APP_ID}
+DESKTOP
+chmod 644 "${DESKTOP_FILE}"
+echo "Wrote ${DESKTOP_FILE}"
+
+refresh_caches
+
+echo
+echo "Done. Triple-C should now be in your app launcher."
+echo "If the icon is generic or the entry is missing, log out and back in —"
+echo "see \"App Icon Missing After Installing (Linux)\" in HOW-TO-USE.md."

scripts/scan-secrets.sh

@@ -0,0 +1,111 @@
+#!/bin/sh
+# Refuse to let a live credential into the repository.
+#
+# Written after one got in: `the_custom_env_fingerprint_never_carries_the_value`
+# used the maintainer's real Gitea site-admin token as its fixture. It survived
+# 92 commits and fourteen days in a public mirror, past five audit rounds and two
+# independent reviews — because every one of those looked at the code under
+# change, and this sat in a test nobody had reason to open. A grep would have
+# caught it on the first day. This is that grep.
+#
+# Usage:
+#   scan-secrets.sh --staged        what `git commit` is about to record (the hook)
+#   scan-secrets.sh --range A..B    every line added between two commits (CI)
+#   scan-secrets.sh --tracked       every tracked file, as it stands now
+#
+# Exit 0 clean, 1 on a finding, 2 on misuse.
+#
+# ## Why it scans *added lines* and not the whole file
+#
+# The repository already contains long opaque strings — 317 literals of 32+
+# characters, almost all of them legitimate. A scanner that failed on those would
+# be turned off within a day, which is the normal way this kind of check dies.
+# Judging only what a commit *adds* keeps the signal where a person can act on it.
+#
+# ## Escape hatch
+#
+# A line carrying `pragma: allowlist secret` is skipped. Deliberately wordy: it
+# should be uncomfortable enough to type that it is read as a claim, and it
+# leaves something greppable behind.
+
+set -eu
+
+MODE="${1:---staged}"
+RANGE="${2:-}"
+
+case "$MODE" in
+  --staged)  ADDED=$(git diff --cached --unified=0 --no-color -- . 2>/dev/null || true) ;;
+  --range)   [ -n "$RANGE" ] || { echo "scan-secrets: --range needs A..B" >&2; exit 2; }
+             ADDED=$(git diff --unified=0 --no-color "$RANGE" -- . 2>/dev/null || true) ;;
+  --tracked)
+             # `grep -Iq .` first: without it a binary blob's bytes reach the
+             # rules below, and GNU grep answers "binary file matches" instead
+             # of the line — so a real finding inside one would be reported as
+             # a sentence nobody can act on, and a stray NUL can end the scan
+             # early. Text files only; binaries are not where source secrets
+             # live, and `--staged` never sees them either (git emits
+             # "Binary files differ", not content).
+             ADDED=$(git ls-files -z \
+               | xargs -0 -I{} sh -c 'grep -Iq . "{}" 2>/dev/null && sed "s/^/+/" "{}" 2>/dev/null' \
+               || true) ;;
+  *)         echo "scan-secrets: unknown mode $MODE" >&2; exit 2 ;;
+esac
+
+# Only added lines; drop diff headers (+++ b/path) so a filename never matches.
+CANDIDATES=$(printf '%s\n' "$ADDED" \
+  | grep '^+' \
+  | grep -v '^+++' \
+  | grep -v 'pragma: allowlist secret' \
+  || true)
+
+[ -n "$CANDIDATES" ] || exit 0
+
+FOUND=0
+report() {
+  FOUND=1
+  printf '\n  %s\n' "$1"
+  printf '%s\n' "$2" | sed 's/^/    /' | cut -c1-160
+}
+
+# --- Rule 1: vendor-issued credentials. Shape alone identifies these, so there
+# --- is no false-positive story to tell and no identifier context needed.
+VENDOR=$(printf '%s\n' "$CANDIDATES" | grep -nE \
+  'gh[pousr]_[A-Za-z0-9]{20,}|github_pat_[A-Za-z0-9_]{20,}|glpat-[A-Za-z0-9_-]{20,}|xox[baprs]-[A-Za-z0-9-]{10,}|sk-[A-Za-z0-9]{32,}|AKIA[0-9A-Z]{16}|ASIA[0-9A-Z]{16}|ya29\.[A-Za-z0-9_-]{20,}|AIza[0-9A-Za-z_-]{35}|npm_[A-Za-z0-9]{36}|dckr_pat_[A-Za-z0-9_-]{20,}' \
+  || true)
+[ -n "$VENDOR" ] && report "A vendor-issued credential (its prefix identifies the provider):" "$VENDOR"
+
+# --- Rule 2: private key material.
+KEYS=$(printf '%s\n' "$CANDIDATES" | grep -nE -- '-----BEGIN [A-Z ]*PRIVATE KEY-----' || true)
+[ -n "$KEYS" ] && report "Private key material:" "$KEYS"
+
+# --- Rule 3: an opaque literal assigned to a secret-shaped name.
+#
+# This is the rule that would have caught the Gitea token — `let secret =
+# "<40 hex>"`. Both halves are required, and that is what keeps it usable:
+# the *name* must read as a credential, and the *whole literal* must be hex or
+# base64 with no word structure. `"aws-secret-access-key"` is a keychain key
+# name sitting right next to the word `secret`, and its hyphens are what keep it
+# out; measured against the tree, name-proximity alone flagged four lines of
+# which three were that shape.
+OPAQUE=$(printf '%s\n' "$CANDIDATES" | grep -niE \
+  '(secret|token|api[_-]?key|apikey|passwo?rd|passwd|credential|auth[_-]?(key|token))[^A-Za-z0-9]{0,12}[:=][^"'"'"']{0,12}["'"'"']([0-9a-fA-F]{32,}|[A-Za-z0-9+/]{40,}={0,2})["'"'"']' \
+  || true)
+[ -n "$OPAQUE" ] && report "An opaque literal assigned to a secret-shaped name:" "$OPAQUE"
+
+if [ "$FOUND" -eq 1 ]; then
+  cat >&2 <<'MSG'
+
+  ────────────────────────────────────────────────────────────────────────
+  Refusing the commit: it adds something shaped like a live credential.
+
+  If it IS live: do not amend and move on. Rotate it first — anything that
+  reaches a branch is on the mirror, and the mirror is public.
+
+  If it is genuinely not a secret — a fixture, a public key id, test data —
+  make the literal obviously fake ("not-a-real-token-0000…"), or append
+  `pragma: allowlist secret` to the line to say so on the record.
+  ────────────────────────────────────────────────────────────────────────
+MSG
+  exit 1
+fi
+exit 0