From 90991fee325f76eaac97555a15ebcd69ddf45537 Mon Sep 17 00:00:00 2001
From: Josh Knapp <jknapp85@gmail.com>
Date: Tue, 22 Sep 2026 21:29:31 -0700
Subject: [PATCH] docs: terminal file viewer structure and capability census

Add CLAUDE.md structure notes for the viewer/ frontend and file_viewer/
backend, plus a Key Conventions reminder that a new local window needs its
own capability file and lib.rs's on_window_event guard. Extend default.json's
threat-model census to name file-viewer.json and its allow-destroy grant.

Tighten the capability test in file_viewer/mod.rs from a substring check to
a parsed serde_json assertion of the exact windows list and permission set
for both capability files, per Task 12's controller ruling.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
---
 CLAUDE.md                                   | 15 +++++++
 app/src-tauri/capabilities/default.json     |  2 +-
 app/src-tauri/gen/schemas/capabilities.json |  2 +-
 app/src-tauri/src/file_viewer/mod.rs        | 50 ++++++++++++++++++++-
 4 files changed, 65 insertions(+), 4 deletions(-)

diff --git a/CLAUDE.md b/CLAUDE.md
index 256ba7f..1da6f56 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -73,6 +73,12 @@ docker exec stdout → tokio task → emit("terminal-output-{sessionId}") → li
 - **`hooks/`** — All Tauri IPC calls are encapsulated in hooks (`useTerminal`, `useProjects`, `useDocker`, `useSettings`)
 - **`lib/tauri-commands.ts`** — Typed `invoke()` wrappers; TypeScript types in `lib/types.ts` must match Rust models
 - **`components/terminal/TerminalView.tsx`** — xterm.js integration with WebGL rendering, URL detection for OAuth flow
+- **`viewer/`** — the terminal file viewer's window (second Vite entry `viewer.html` →
+  `src/viewer/main.tsx`; CodeMirror 6). `lib/filePathLinks.ts` decides what a path is;
+  `components/terminal/filePathLinkProvider.ts` registers it with xterm. The OSC 8 handler now
+  runs with `allowNonHttpProtocols` on and dispatches `file:` to the viewer, so every other scheme
+  must be refused *there*. `viewer.html` must never carry an inline `<style>` — Tauri would add a
+  style nonce and CodeMirror's injected styles would stop applying.
 - **`components/layout/`** — TopBar, MainTabs (the unified tab strip), Sidebar, StatusBar
 - **`components/projects/`** — `ProjectRow` (select-only list row), `ProjectList`, `AddProjectDialog`,
   and the editors reused by Project Home
@@ -161,6 +167,13 @@ docker exec stdout → tokio task → emit("terminal-output-{sessionId}") → li
   Beyond docker/project/settings/terminal: `inspect_commands.rs` (read-only views into a
   container — Claude sessions, installed capabilities, scheduler tasks), `auth_bridge_commands.rs`,
   `auth_token_commands.rs`.
+- **`file_viewer/`** — one window per click (`file-viewer-<n>`), a managed `ViewerRegistry`,
+  resolution by probing `/workspace/<p>` then `/workspace/<mount>/<p>` in one exec as `claude`,
+  polling by `sha256sum`, saves staged in `/tmp` and swapped in by a `sh` script as the container
+  user (spec §5 says why the archive API never writes to the target directory). Commands take
+  `window: tauri::Window`, gate on the label and act on the caller's own registry entry — no
+  viewer command accepts a path. The residual risk that any local window can call any app command
+  is deliberate and documented; the AppManifest lockdown spec closes it.
 - **`auth_bridge/`** — Host-side loopback bridge so browser logins run *inside* a container can
   complete against the host browser. Discovers listeners by parsing `/proc/net/tcp{,6}` (the image
   has no `ss`/`netstat`/`lsof`), binds host `127.0.0.1` **only**, and tunnels in over the Docker
@@ -601,6 +614,8 @@ Anthropic and Bedrock deliberately keep Claude Code's own defaults.
   `#[serde(default)]` on a `bool` yields `false`; follow the `default_full_permissions` pattern in
   `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
+- A new local window needs its own capability file (`capabilities/file-viewer.json` is the
+  model), and `lib.rs`'s `on_window_event` stays guarded on `label() == "main"`.
 
 ## Secrets
 
diff --git a/app/src-tauri/capabilities/default.json b/app/src-tauri/capabilities/default.json
index 63e7777..2a21e48 100644
--- a/app/src-tauri/capabilities/default.json
+++ b/app/src-tauri/capabilities/default.json
@@ -1,6 +1,6 @@
 {
   "identifier": "default",
-  "description": "Default capabilities for Triple-C. Every entry here is an IPC command a compromised webview can call directly, so the set is an enumeration of what `app/src` actually invokes — verified against tauri 2.11.0's `PLUGINS` table in `build.rs`, not assumed from a plugin's `default` set. `core:default` in particular is NOT used: it is an alias for `core:{path,event,window,webview,app,image,resources,menu,tray}:default`, and `core:image:default` carries `allow-from-path`, whose handler (`tauri-2.11.0/src/image/plugin.rs:41` → `src/image/mod.rs:96`) is a bare `std::fs::read(path)` with no scope mechanism of any kind. Nothing imports `@tauri-apps/api/image`, so the whole plugin is dropped rather than scoped — there is nothing to scope it with. `core:menu` and `core:tray` are dropped for the same reason (no menu, no tray icon); `core:window` and `core:path` because nothing imports them; `core:resources:allow-close` because no frontend value is a `Resource`; and `core:event`'s `allow-emit`/`allow-emit-to` because the frontend only ever *listens* — every emit in this app originates in Rust. Three notes on what is deliberately kept or accepted: (1) `core:webview:allow-internal-toggle-devtools` is not called by `app/src` at all — it is called by Tauri's own injected `toggle-devtools.js`, which binds Ctrl/Cmd+Shift+I. Both that script and the command behind it are `#[cfg(any(debug_assertions, feature = \"devtools\"))]`, so this grant is a `tauri dev` convenience that does not exist in a release bundle. (2) `opener:allow-open-url` is **gone**. It could not be narrowed by host \u2014 `TerminalView`'s `WebLinksAddon` opens links Claude printed inside the container, which are arbitrary by construction, so a host allowlist would have deleted the feature rather than bounded it \u2014 and it was carried here as an accepted residual risk: a compromised webview could make the OS open an attacker-chosen http(s) URL, an outbound channel. That risk is now closed rather than recorded. Every host-browser open in the app goes through the `open_url_external` command in `url_open.rs`, which exists because the AppImage environment leaks into a cold-launched browser on Linux (triple-c#34) and which re-validates the URL in Rust \u2014 scheme allowlist, no embedded credentials, no control characters, length cap, ASCII asserted before `execvp`. On macOS and Windows that command reaches the same plugin as before, via `OpenerExt::open_url`, whose desktop implementation calls `crate::open::open` directly and is therefore not gated by this file at all (`tauri-plugin-opener-2.5.3/src/lib.rs:60`). The plugin stays a dependency for exactly that reason; what is removed is the webview's ability to reach it without passing the Rust validation. (3) `drag:allow-start-drag` is **gone**, together with the OS drag-out it existed for. It could not be scoped — `tauri-plugin-drag` takes the item paths from the caller and has no scope mechanism, so a compromised webview could call `startDrag({ item: ['~/.ssh/id_rsa'] })` against any host path the user can read — and it was carried as an accepted residual risk for one gesture. Drag-out was held back for separate hardening (see branch `hold/disk-and-dragout`) and the plugin is no longer a dependency. Getting a file *out* of a container is either \"Back up container\" on the project's Overview tab, which archives a tree through the Docker API, or the Files tab's per-row \"Save to host…\", which copies one file; getting one *in* is a drop on the Terminal or the Files tab's \"Upload…\". None of the four touches this permission. The Files tab's two are worth separating out here, because they are the only host-path commands in the app whose dialog is opened by **Rust** rather than by the webview — `pick_save_path` and `pick_files_to_upload` in `commands/file_commands.rs` drive `tauri-plugin-dialog` from the backend, so a compromised webview can ask for a picker and nothing more: it cannot name a host path as an *input* to either command. Be precise about the limit of that claim — host paths do still travel outward in error text (`Failed to create /home/j/Documents/x.txt.triple-c-part-1a2b3c4d: Permission denied`), including canonicalized ones, which disclose symlink targets. That is accepted; the app already hands the webview the project paths. What is closed is the direction that mattered — the webview naming where bytes go. That is the shape an earlier revision of this file named as the honest one if the Files tab ever regained host I/O, and it is the shape it regained it in. The `dialog:allow-open` / `dialog:allow-save` grants below are therefore *not* what those two use; they remain for the frontend pickers in Add Project, the Config tab's workspace and access sections, the CA-certificate field and Backup. Two commands still take a host path over IPC as a string — the terminal drop and `download_container_backup` — and for those `validate_host_path` is the boundary rather than defence in depth. This file is the reviewed threat model of record, so keep this census accurate: a stale reference here is worse than none. Note that dragging files *into* the app is unaffected: `dragDropEnabled` and `onDragDropEvent` are core webview behaviour and need no grant. Historical note kept because it is easy to re-introduce: the `store:*` grants were removed — nothing in `app/src` uses `@tauri-apps/plugin-store`, and the plugin's `resolve_store_path` is a `PathBuf::push` against AppData, which `push` discards outright when handed an absolute path, so the grant was an arbitrary host-file read/write primitive (`plugin:store|load` + `set` + `save` on `~/.claude/settings.json` is host code execution). On the CSP side: `app.security.csp` in `tauri.conf.json` covers the shipped bundle, and there is deliberately no `devCsp`. `npm run tauri dev` loads the main document straight from Vite at `build.devUrl` (`http://localhost:1420`), and Tauri only attaches a CSP to documents it serves itself — `protocol/tauri.rs:217` sets the header on `tauri://` assets, and the dev server is proxied through that protocol only when `PROXY_DEV_SERVER`, which is `cfg!(all(dev, mobile))` and therefore false for every desktop build. A `devCsp` here would be inert config that reads as protection, which is worse than its absence. If a CSP in dev is wanted, the only place that can set one is the Vite dev server's own `server.headers` in `app/vite.config.ts`; it is not set today, and dev is not the shipped configuration.",
+  "description": "Default capabilities for Triple-C. Every entry here is an IPC command a compromised webview can call directly, so the set is an enumeration of what `app/src` actually invokes — verified against tauri 2.11.0's `PLUGINS` table in `build.rs`, not assumed from a plugin's `default` set. `core:default` in particular is NOT used: it is an alias for `core:{path,event,window,webview,app,image,resources,menu,tray}:default`, and `core:image:default` carries `allow-from-path`, whose handler (`tauri-2.11.0/src/image/plugin.rs:41` → `src/image/mod.rs:96`) is a bare `std::fs::read(path)` with no scope mechanism of any kind. Nothing imports `@tauri-apps/api/image`, so the whole plugin is dropped rather than scoped — there is nothing to scope it with. `core:menu` and `core:tray` are dropped for the same reason (no menu, no tray icon); `core:window` and `core:path` because nothing imports them; `core:resources:allow-close` because no frontend value is a `Resource`; and `core:event`'s `allow-emit`/`allow-emit-to` because the frontend only ever *listens* — every emit in this app originates in Rust. Three notes on what is deliberately kept or accepted: (1) `core:webview:allow-internal-toggle-devtools` is not called by `app/src` at all — it is called by Tauri's own injected `toggle-devtools.js`, which binds Ctrl/Cmd+Shift+I. Both that script and the command behind it are `#[cfg(any(debug_assertions, feature = \"devtools\"))]`, so this grant is a `tauri dev` convenience that does not exist in a release bundle. (2) `opener:allow-open-url` is **gone**. It could not be narrowed by host \u2014 `TerminalView`'s `WebLinksAddon` opens links Claude printed inside the container, which are arbitrary by construction, so a host allowlist would have deleted the feature rather than bounded it \u2014 and it was carried here as an accepted residual risk: a compromised webview could make the OS open an attacker-chosen http(s) URL, an outbound channel. That risk is now closed rather than recorded. Every host-browser open in the app goes through the `open_url_external` command in `url_open.rs`, which exists because the AppImage environment leaks into a cold-launched browser on Linux (triple-c#34) and which re-validates the URL in Rust \u2014 scheme allowlist, no embedded credentials, no control characters, length cap, ASCII asserted before `execvp`. On macOS and Windows that command reaches the same plugin as before, via `OpenerExt::open_url`, whose desktop implementation calls `crate::open::open` directly and is therefore not gated by this file at all (`tauri-plugin-opener-2.5.3/src/lib.rs:60`). The plugin stays a dependency for exactly that reason; what is removed is the webview's ability to reach it without passing the Rust validation. (3) `drag:allow-start-drag` is **gone**, together with the OS drag-out it existed for. It could not be scoped — `tauri-plugin-drag` takes the item paths from the caller and has no scope mechanism, so a compromised webview could call `startDrag({ item: ['~/.ssh/id_rsa'] })` against any host path the user can read — and it was carried as an accepted residual risk for one gesture. Drag-out was held back for separate hardening (see branch `hold/disk-and-dragout`) and the plugin is no longer a dependency. Getting a file *out* of a container is either \"Back up container\" on the project's Overview tab, which archives a tree through the Docker API, or the Files tab's per-row \"Save to host…\", which copies one file; getting one *in* is a drop on the Terminal or the Files tab's \"Upload…\". None of the four touches this permission. The Files tab's two are worth separating out here, because they are the only host-path commands in the app whose dialog is opened by **Rust** rather than by the webview — `pick_save_path` and `pick_files_to_upload` in `commands/file_commands.rs` drive `tauri-plugin-dialog` from the backend, so a compromised webview can ask for a picker and nothing more: it cannot name a host path as an *input* to either command. Be precise about the limit of that claim — host paths do still travel outward in error text (`Failed to create /home/j/Documents/x.txt.triple-c-part-1a2b3c4d: Permission denied`), including canonicalized ones, which disclose symlink targets. That is accepted; the app already hands the webview the project paths. What is closed is the direction that mattered — the webview naming where bytes go. That is the shape an earlier revision of this file named as the honest one if the Files tab ever regained host I/O, and it is the shape it regained it in. The `dialog:allow-open` / `dialog:allow-save` grants below are therefore *not* what those two use; they remain for the frontend pickers in Add Project, the Config tab's workspace and access sections, the CA-certificate field and Backup. Two commands still take a host path over IPC as a string — the terminal drop and `download_container_backup` — and for those `validate_host_path` is the boundary rather than defence in depth. This file is the reviewed threat model of record, so keep this census accurate: a stale reference here is worse than none. Note that dragging files *into* the app is unaffected: `dragDropEnabled` and `onDragDropEvent` are core webview behaviour and need no grant. Historical note kept because it is easy to re-introduce: the `store:*` grants were removed — nothing in `app/src` uses `@tauri-apps/plugin-store`, and the plugin's `resolve_store_path` is a `PathBuf::push` against AppData, which `push` discards outright when handed an absolute path, so the grant was an arbitrary host-file read/write primitive (`plugin:store|load` + `set` + `save` on `~/.claude/settings.json` is host code execution). A second capability file, `file-viewer.json`, covers the `file-viewer-*` windows the terminal file viewer opens on `viewer.html`; it is the only other local-origin window, its grants are listed and justified there, and its one non-obvious grant (`core:window:allow-destroy`) exists because `onCloseRequested` cannot close a window without it. App commands stay ungated by capability in both files; the viewer's are gated by label in `commands/file_viewer_commands.rs`. On the CSP side: `app.security.csp` in `tauri.conf.json` covers the shipped bundle, and there is deliberately no `devCsp`. `npm run tauri dev` loads the main document straight from Vite at `build.devUrl` (`http://localhost:1420`), and Tauri only attaches a CSP to documents it serves itself — `protocol/tauri.rs:217` sets the header on `tauri://` assets, and the dev server is proxied through that protocol only when `PROXY_DEV_SERVER`, which is `cfg!(all(dev, mobile))` and therefore false for every desktop build. A `devCsp` here would be inert config that reads as protection, which is worse than its absence. If a CSP in dev is wanted, the only place that can set one is the Vite dev server's own `server.headers` in `app/vite.config.ts`; it is not set today, and dev is not the shipped configuration.",
   "windows": ["main"],
   "permissions": [
     "core:event:allow-listen",
diff --git a/app/src-tauri/gen/schemas/capabilities.json b/app/src-tauri/gen/schemas/capabilities.json
index 8a6340b..8e3e5b7 100644
--- a/app/src-tauri/gen/schemas/capabilities.json
+++ b/app/src-tauri/gen/schemas/capabilities.json
@@ -1 +1 @@
-{"default":{"identifier":"default","description":"Default capabilities for Triple-C. Every entry here is an IPC command a compromised webview can call directly, so the set is an enumeration of what `app/src` actually invokes — verified against tauri 2.11.0's `PLUGINS` table in `build.rs`, not assumed from a plugin's `default` set. `core:default` in particular is NOT used: it is an alias for `core:{path,event,window,webview,app,image,resources,menu,tray}:default`, and `core:image:default` carries `allow-from-path`, whose handler (`tauri-2.11.0/src/image/plugin.rs:41` → `src/image/mod.rs:96`) is a bare `std::fs::read(path)` with no scope mechanism of any kind. Nothing imports `@tauri-apps/api/image`, so the whole plugin is dropped rather than scoped — there is nothing to scope it with. `core:menu` and `core:tray` are dropped for the same reason (no menu, no tray icon); `core:window` and `core:path` because nothing imports them; `core:resources:allow-close` because no frontend value is a `Resource`; and `core:event`'s `allow-emit`/`allow-emit-to` because the frontend only ever *listens* — every emit in this app originates in Rust. Three notes on what is deliberately kept or accepted: (1) `core:webview:allow-internal-toggle-devtools` is not called by `app/src` at all — it is called by Tauri's own injected `toggle-devtools.js`, which binds Ctrl/Cmd+Shift+I. Both that script and the command behind it are `#[cfg(any(debug_assertions, feature = \"devtools\"))]`, so this grant is a `tauri dev` convenience that does not exist in a release bundle. (2) `opener:allow-open-url` is **gone**. It could not be narrowed by host — `TerminalView`'s `WebLinksAddon` opens links Claude printed inside the container, which are arbitrary by construction, so a host allowlist would have deleted the feature rather than bounded it — and it was carried here as an accepted residual risk: a compromised webview could make the OS open an attacker-chosen http(s) URL, an outbound channel. That risk is now closed rather than recorded. Every host-browser open in the app goes through the `open_url_external` command in `url_open.rs`, which exists because the AppImage environment leaks into a cold-launched browser on Linux (triple-c#34) and which re-validates the URL in Rust — scheme allowlist, no embedded credentials, no control characters, length cap, ASCII asserted before `execvp`. On macOS and Windows that command reaches the same plugin as before, via `OpenerExt::open_url`, whose desktop implementation calls `crate::open::open` directly and is therefore not gated by this file at all (`tauri-plugin-opener-2.5.3/src/lib.rs:60`). The plugin stays a dependency for exactly that reason; what is removed is the webview's ability to reach it without passing the Rust validation. (3) `drag:allow-start-drag` is **gone**, together with the OS drag-out it existed for. It could not be scoped — `tauri-plugin-drag` takes the item paths from the caller and has no scope mechanism, so a compromised webview could call `startDrag({ item: ['~/.ssh/id_rsa'] })` against any host path the user can read — and it was carried as an accepted residual risk for one gesture. Drag-out was held back for separate hardening (see branch `hold/disk-and-dragout`) and the plugin is no longer a dependency. Getting a file *out* of a container is either \"Back up container\" on the project's Overview tab, which archives a tree through the Docker API, or the Files tab's per-row \"Save to host…\", which copies one file; getting one *in* is a drop on the Terminal or the Files tab's \"Upload…\". None of the four touches this permission. The Files tab's two are worth separating out here, because they are the only host-path commands in the app whose dialog is opened by **Rust** rather than by the webview — `pick_save_path` and `pick_files_to_upload` in `commands/file_commands.rs` drive `tauri-plugin-dialog` from the backend, so a compromised webview can ask for a picker and nothing more: it cannot name a host path as an *input* to either command. Be precise about the limit of that claim — host paths do still travel outward in error text (`Failed to create /home/j/Documents/x.txt.triple-c-part-1a2b3c4d: Permission denied`), including canonicalized ones, which disclose symlink targets. That is accepted; the app already hands the webview the project paths. What is closed is the direction that mattered — the webview naming where bytes go. That is the shape an earlier revision of this file named as the honest one if the Files tab ever regained host I/O, and it is the shape it regained it in. The `dialog:allow-open` / `dialog:allow-save` grants below are therefore *not* what those two use; they remain for the frontend pickers in Add Project, the Config tab's workspace and access sections, the CA-certificate field and Backup. Two commands still take a host path over IPC as a string — the terminal drop and `download_container_backup` — and for those `validate_host_path` is the boundary rather than defence in depth. This file is the reviewed threat model of record, so keep this census accurate: a stale reference here is worse than none. Note that dragging files *into* the app is unaffected: `dragDropEnabled` and `onDragDropEvent` are core webview behaviour and need no grant. Historical note kept because it is easy to re-introduce: the `store:*` grants were removed — nothing in `app/src` uses `@tauri-apps/plugin-store`, and the plugin's `resolve_store_path` is a `PathBuf::push` against AppData, which `push` discards outright when handed an absolute path, so the grant was an arbitrary host-file read/write primitive (`plugin:store|load` + `set` + `save` on `~/.claude/settings.json` is host code execution). On the CSP side: `app.security.csp` in `tauri.conf.json` covers the shipped bundle, and there is deliberately no `devCsp`. `npm run tauri dev` loads the main document straight from Vite at `build.devUrl` (`http://localhost:1420`), and Tauri only attaches a CSP to documents it serves itself — `protocol/tauri.rs:217` sets the header on `tauri://` assets, and the dev server is proxied through that protocol only when `PROXY_DEV_SERVER`, which is `cfg!(all(dev, mobile))` and therefore false for every desktop build. A `devCsp` here would be inert config that reads as protection, which is worse than its absence. If a CSP in dev is wanted, the only place that can set one is the Vite dev server's own `server.headers` in `app/vite.config.ts`; it is not set today, and dev is not the shipped configuration.","local":true,"windows":["main"],"permissions":["core:event:allow-listen","core:event:allow-unlisten","core:webview:allow-internal-toggle-devtools","dialog:allow-open","dialog:allow-save"]},"file-viewer":{"identifier":"file-viewer","description":"The terminal file viewer windows (`file-viewer-<n>`, opened by `open_file_viewer` on the app's own `viewer.html`). Same rules as `default.json`: app commands need no entry here and are gated by label inside `commands/file_viewer_commands.rs`; this file is the plugin-command surface a compromised viewer webview could reach, and it is the smallest one that lets the window work. `core:event:allow-listen`/`allow-unlisten` are for `file-viewer-goto` (Rust → this window; the viewer subscribes through `getCurrentWindow().listen`, because a bare `listen()` in *any* window receives an `emit_to`). `core:window:allow-destroy` is not optional: `getCurrentWindow().onCloseRequested` in @tauri-apps/api 2.11 makes Rust `prevent_close()` whenever a JS listener exists and then calls `destroy()` itself, so without this grant the window's X button does nothing once the unsaved-changes guard is installed. `allow-close` is deliberately absent — nothing calls it, and `destroy` is the only exit. No `set-title`/`set-focus`/`unminimize`: those are done from Rust when a second click targets an already-open file. `core:webview:allow-internal-toggle-devtools` is the same dev-only convenience `default.json` carries.","local":true,"windows":["file-viewer-*"],"permissions":["core:event:allow-listen","core:event:allow-unlisten","core:window:allow-destroy","core:webview:allow-internal-toggle-devtools"]}}
\ No newline at end of file
+{"default":{"identifier":"default","description":"Default capabilities for Triple-C. Every entry here is an IPC command a compromised webview can call directly, so the set is an enumeration of what `app/src` actually invokes — verified against tauri 2.11.0's `PLUGINS` table in `build.rs`, not assumed from a plugin's `default` set. `core:default` in particular is NOT used: it is an alias for `core:{path,event,window,webview,app,image,resources,menu,tray}:default`, and `core:image:default` carries `allow-from-path`, whose handler (`tauri-2.11.0/src/image/plugin.rs:41` → `src/image/mod.rs:96`) is a bare `std::fs::read(path)` with no scope mechanism of any kind. Nothing imports `@tauri-apps/api/image`, so the whole plugin is dropped rather than scoped — there is nothing to scope it with. `core:menu` and `core:tray` are dropped for the same reason (no menu, no tray icon); `core:window` and `core:path` because nothing imports them; `core:resources:allow-close` because no frontend value is a `Resource`; and `core:event`'s `allow-emit`/`allow-emit-to` because the frontend only ever *listens* — every emit in this app originates in Rust. Three notes on what is deliberately kept or accepted: (1) `core:webview:allow-internal-toggle-devtools` is not called by `app/src` at all — it is called by Tauri's own injected `toggle-devtools.js`, which binds Ctrl/Cmd+Shift+I. Both that script and the command behind it are `#[cfg(any(debug_assertions, feature = \"devtools\"))]`, so this grant is a `tauri dev` convenience that does not exist in a release bundle. (2) `opener:allow-open-url` is **gone**. It could not be narrowed by host — `TerminalView`'s `WebLinksAddon` opens links Claude printed inside the container, which are arbitrary by construction, so a host allowlist would have deleted the feature rather than bounded it — and it was carried here as an accepted residual risk: a compromised webview could make the OS open an attacker-chosen http(s) URL, an outbound channel. That risk is now closed rather than recorded. Every host-browser open in the app goes through the `open_url_external` command in `url_open.rs`, which exists because the AppImage environment leaks into a cold-launched browser on Linux (triple-c#34) and which re-validates the URL in Rust — scheme allowlist, no embedded credentials, no control characters, length cap, ASCII asserted before `execvp`. On macOS and Windows that command reaches the same plugin as before, via `OpenerExt::open_url`, whose desktop implementation calls `crate::open::open` directly and is therefore not gated by this file at all (`tauri-plugin-opener-2.5.3/src/lib.rs:60`). The plugin stays a dependency for exactly that reason; what is removed is the webview's ability to reach it without passing the Rust validation. (3) `drag:allow-start-drag` is **gone**, together with the OS drag-out it existed for. It could not be scoped — `tauri-plugin-drag` takes the item paths from the caller and has no scope mechanism, so a compromised webview could call `startDrag({ item: ['~/.ssh/id_rsa'] })` against any host path the user can read — and it was carried as an accepted residual risk for one gesture. Drag-out was held back for separate hardening (see branch `hold/disk-and-dragout`) and the plugin is no longer a dependency. Getting a file *out* of a container is either \"Back up container\" on the project's Overview tab, which archives a tree through the Docker API, or the Files tab's per-row \"Save to host…\", which copies one file; getting one *in* is a drop on the Terminal or the Files tab's \"Upload…\". None of the four touches this permission. The Files tab's two are worth separating out here, because they are the only host-path commands in the app whose dialog is opened by **Rust** rather than by the webview — `pick_save_path` and `pick_files_to_upload` in `commands/file_commands.rs` drive `tauri-plugin-dialog` from the backend, so a compromised webview can ask for a picker and nothing more: it cannot name a host path as an *input* to either command. Be precise about the limit of that claim — host paths do still travel outward in error text (`Failed to create /home/j/Documents/x.txt.triple-c-part-1a2b3c4d: Permission denied`), including canonicalized ones, which disclose symlink targets. That is accepted; the app already hands the webview the project paths. What is closed is the direction that mattered — the webview naming where bytes go. That is the shape an earlier revision of this file named as the honest one if the Files tab ever regained host I/O, and it is the shape it regained it in. The `dialog:allow-open` / `dialog:allow-save` grants below are therefore *not* what those two use; they remain for the frontend pickers in Add Project, the Config tab's workspace and access sections, the CA-certificate field and Backup. Two commands still take a host path over IPC as a string — the terminal drop and `download_container_backup` — and for those `validate_host_path` is the boundary rather than defence in depth. This file is the reviewed threat model of record, so keep this census accurate: a stale reference here is worse than none. Note that dragging files *into* the app is unaffected: `dragDropEnabled` and `onDragDropEvent` are core webview behaviour and need no grant. Historical note kept because it is easy to re-introduce: the `store:*` grants were removed — nothing in `app/src` uses `@tauri-apps/plugin-store`, and the plugin's `resolve_store_path` is a `PathBuf::push` against AppData, which `push` discards outright when handed an absolute path, so the grant was an arbitrary host-file read/write primitive (`plugin:store|load` + `set` + `save` on `~/.claude/settings.json` is host code execution). A second capability file, `file-viewer.json`, covers the `file-viewer-*` windows the terminal file viewer opens on `viewer.html`; it is the only other local-origin window, its grants are listed and justified there, and its one non-obvious grant (`core:window:allow-destroy`) exists because `onCloseRequested` cannot close a window without it. App commands stay ungated by capability in both files; the viewer's are gated by label in `commands/file_viewer_commands.rs`. On the CSP side: `app.security.csp` in `tauri.conf.json` covers the shipped bundle, and there is deliberately no `devCsp`. `npm run tauri dev` loads the main document straight from Vite at `build.devUrl` (`http://localhost:1420`), and Tauri only attaches a CSP to documents it serves itself — `protocol/tauri.rs:217` sets the header on `tauri://` assets, and the dev server is proxied through that protocol only when `PROXY_DEV_SERVER`, which is `cfg!(all(dev, mobile))` and therefore false for every desktop build. A `devCsp` here would be inert config that reads as protection, which is worse than its absence. If a CSP in dev is wanted, the only place that can set one is the Vite dev server's own `server.headers` in `app/vite.config.ts`; it is not set today, and dev is not the shipped configuration.","local":true,"windows":["main"],"permissions":["core:event:allow-listen","core:event:allow-unlisten","core:webview:allow-internal-toggle-devtools","dialog:allow-open","dialog:allow-save"]},"file-viewer":{"identifier":"file-viewer","description":"The terminal file viewer windows (`file-viewer-<n>`, opened by `open_file_viewer` on the app's own `viewer.html`). Same rules as `default.json`: app commands need no entry here and are gated by label inside `commands/file_viewer_commands.rs`; this file is the plugin-command surface a compromised viewer webview could reach, and it is the smallest one that lets the window work. `core:event:allow-listen`/`allow-unlisten` are for `file-viewer-goto` (Rust → this window; the viewer subscribes through `getCurrentWindow().listen`, because a bare `listen()` in *any* window receives an `emit_to`). `core:window:allow-destroy` is not optional: `getCurrentWindow().onCloseRequested` in @tauri-apps/api 2.11 makes Rust `prevent_close()` whenever a JS listener exists and then calls `destroy()` itself, so without this grant the window's X button does nothing once the unsaved-changes guard is installed. `allow-close` is deliberately absent — nothing calls it, and `destroy` is the only exit. No `set-title`/`set-focus`/`unminimize`: those are done from Rust when a second click targets an already-open file. `core:webview:allow-internal-toggle-devtools` is the same dev-only convenience `default.json` carries.","local":true,"windows":["file-viewer-*"],"permissions":["core:event:allow-listen","core:event:allow-unlisten","core:window:allow-destroy","core:webview:allow-internal-toggle-devtools"]}}
\ No newline at end of file
diff --git a/app/src-tauri/src/file_viewer/mod.rs b/app/src-tauri/src/file_viewer/mod.rs
index 0a8f925..d07272e 100644
--- a/app/src-tauri/src/file_viewer/mod.rs
+++ b/app/src-tauri/src/file_viewer/mod.rs
@@ -45,7 +45,53 @@ mod tests {
         assert!(!html.contains("<style"), "an inline <style> makes Tauri add a style nonce, which disables 'unsafe-inline' and breaks CodeMirror");
         let vite = std::fs::read_to_string(app_dir.join("vite.config.ts")).expect("vite.config.ts");
         assert!(vite.contains("viewer.html"), "vite.config.ts must list viewer.html in build.rollupOptions.input");
-        let cap = std::fs::read_to_string(app_dir.join("src-tauri/capabilities/file-viewer.json")).expect("capability");
-        assert!(cap.contains("\"file-viewer-*\"") && cap.contains("core:window:allow-destroy"));
+    }
+
+    #[derive(serde::Deserialize)]
+    struct Capability {
+        windows: Vec<String>,
+        permissions: Vec<String>,
+    }
+
+    /// Task 12: a substring check on the capability JSON (the form this test used to take)
+    /// only proves a permission string appears *somewhere* in the file — it would not catch
+    /// `windows` widened past `file-viewer-*`, nor an extra grant slipped in beside the ones
+    /// this window actually needs. Parse both capability files and pin `windows`/`permissions`
+    /// exactly, so a later widening of either file is a failing test, not a silent threat-model
+    /// drift — this file *is* the reviewed threat model of record (see its own description).
+    #[test]
+    fn the_viewer_capability_grants_exactly_the_reviewed_windows_and_permissions() {
+        let app_dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("..");
+        let raw = std::fs::read_to_string(app_dir.join("src-tauri/capabilities/file-viewer.json"))
+            .expect("capabilities/file-viewer.json");
+        let cap: Capability = serde_json::from_str(&raw).expect("file-viewer.json must be valid JSON");
+
+        assert_eq!(cap.windows, vec!["file-viewer-*"]);
+
+        let mut permissions = cap.permissions;
+        permissions.sort();
+        assert_eq!(
+            permissions,
+            vec![
+                "core:event:allow-listen",
+                "core:event:allow-unlisten",
+                "core:webview:allow-internal-toggle-devtools",
+                "core:window:allow-destroy",
+            ]
+        );
+    }
+
+    /// The main window's capability file must stay scoped to `main` — a `windows` list that
+    /// grew to include `file-viewer-*` would hand every viewer window the dialog/store surface
+    /// `default.json` grants `main`, which is a much larger IPC surface than the one
+    /// `file-viewer.json` was deliberately kept small.
+    #[test]
+    fn the_default_capability_is_scoped_to_the_main_window_only() {
+        let app_dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("..");
+        let raw = std::fs::read_to_string(app_dir.join("src-tauri/capabilities/default.json"))
+            .expect("capabilities/default.json");
+        let cap: Capability = serde_json::from_str(&raw).expect("default.json must be valid JSON");
+
+        assert_eq!(cap.windows, vec!["main"]);
     }
 }