Merge pull request 'Let a project's container run a VPN client' (#27) from feat/vpn-support into main

Review caught that the device guard was wired to the wrong call. The
daemon does not resolve `--device` at create: verified against Docker
29.7, `docker create --device /dev/does-not-exist` succeeds and prints an
id, and runc only resolves the device — and validates sysctls — when it
builds the container. So on a host with no tun module the create returns
fine and `start` fails, which means the explanation never ran and the
user saw the raw daemon string naming a path they would go looking for on
the wrong machine. The unit tests fed the create-side string straight in,
so they confirmed a function no real failure could reach.

Move the guard onto `start_container`, covering create as well in case a
future daemon checks earlier. It no longer takes `vpn_support_enabled` —
`start_container` has a container id and no project, and nothing else in
Triple-C ever requests a device, so an error naming /dev/net/tun is
unambiguous on its own. The test now uses the daemon's verbatim message
via bollard's real Display format.

Also from review:

  * Soften the security claim. Docker does not enable user-namespace
    remapping by default, so this is a real CAP_NET_ADMIN in the initial
    user namespace with only the network namespace confining it. It
    cannot touch host interfaces, but "confers no authority outside the
    container" was too strong: within its namespace it can set
    promiscuous mode and add addresses, routes and NAT on the shared
    docker0 segment, which puts sibling containers — the LiteLLM gateway
    among them — within ARP-spoofing reach, and it can flush netfilter
    rules sandbox mode may rely on. Said plainly in the code, CLAUDE.md
    and HOW-TO-USE.
  * Drop Tailscale from the list of clients needing this. Its
    --tun=userspace-networking mode needs neither the capability nor the
    device, and listing it invites granting NET_ADMIN for nothing.
  * Say in the toggle's own hint that changing it recreates the
    container, matching how every other recreation-triggering setting is
    labelled. The tab's generic "stop the container first" chip does not
    tell the user what is about to happen.
  * Add RuntimeSection tests: saves on, saves off explicitly rather than
    dropping the key, reflects state, is disabled while running, and
    carries the recreation warning.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.gitea/workflows/build-app.yml

@@ -39,13 +39,48 @@ jobs:
           MAJOR_MINOR=$(cat VERSION | tr -d '[:space:]')
           echo "Major.Minor: ${MAJOR_MINOR}"
 
-          # Find the latest tag matching v{MAJOR_MINOR}.N (exclude -mac, -win suffixes)
-          # `|| true` so an empty grep result doesn't fail the step under pipefail.
-          LATEST_TAG=$(git tag -l "v${MAJOR_MINOR}.*" --sort=-v:refname | grep -E "^v${MAJOR_MINOR}\.[0-9]+$" | head -1 || true)
+          # The patch number is **one past the highest patch already used**, and
+          # never a distance.
+          #
+          # It used to be `git rev-list --count <highest tag>..HEAD`, which is
+          # not a counter at all: it measures how far HEAD has drifted from
+          # whichever tag sorts highest, and that resets to zero every time a
+          # tag is cut. The published history is the proof — each of these is
+          # exactly what the old formula returned at the time:
+          #
+          #   v0.4.0 -> 3 commits -> v0.4.3    looked fine
+          #   v0.4.3 -> 4 commits -> v0.4.4    fine by luck, 4 > 3
+          #   v0.4.4 -> 2 commits -> v0.4.2    went backwards
+          #   v0.4.4 -> 6 commits -> v0.4.6    jumped, skipping .5
+          #   v0.4.6 -> 3 commits -> v0.4.3    already taken; the upload failed
+          #
+          # Reusing a version is worse than failing to publish one: the macOS
+          # and Windows steps replace assets in place, so a duplicate silently
+          # rewrote a release that had been public for three days. Monotonic
+          # numbering is what stops that at the source.
+          #
+          # Suffixed tags count too. `create-tag` is skipped when any platform
+          # job fails, so a run can publish v0.4.7-mac and never create the
+          # plain v0.4.7 — reading only unsuffixed tags would then hand the
+          # same number out twice.
+          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)
 
-          if [ -n "$LATEST_TAG" ]; then
-            echo "Latest matching tag: ${LATEST_TAG}"
-            PATCH=$(git rev-list --count "${LATEST_TAG}..HEAD")
+          # A re-run of a commit that already released must not mint a new
+          # version just because its own tag now exists.
+          EXISTING=$(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}.${EXISTING} — reusing it"
+            PATCH="${EXISTING}"
+          elif [ -n "$HIGHEST" ]; then
+            echo "Highest patch already used on this line: ${HIGHEST}"
+            PATCH=$((HIGHEST + 1))
           else
             # A minor line nobody has tagged yet is a *new* line, and a new line
             # starts at .0 — that is what "we are moving to 0.4.x" means. The
@@ -165,21 +200,70 @@ jobs:
         env:
           TOKEN: ${{ secrets.REGISTRY_TOKEN }}
         run: |
+          set -euo pipefail
           TAG="v${{ needs.compute-version.outputs.version }}"
-          # Create release
-          curl -s -X POST \
+
+          # Idempotent get-or-create, matching build-macos. This step used to
+          # POST /releases unconditionally: against a tag that already existed
+          # Gitea answered 409, the grep below found no id, and the run died
+          # with a bare "exitcode '1'" and not one line of output explaining
+          # it — `curl -s` with no `-f` swallows the HTTP error, so nothing
+          # ever said "409" or "duplicate tag". Hence -fsS throughout, and
+          # pipefail so a failure cannot be stepped over.
+          HTTP_CODE=$(curl -sS -o release.json -w '%{http_code}' \
             -H "Authorization: token ${TOKEN}" \
-            -H "Content-Type: application/json" \
-            -d "{\"tag_name\": \"${TAG}\", \"name\": \"Triple-C ${TAG} (Linux)\", \"body\": \"Automated build from commit ${{ gitea.sha }}\"}" \
-            "${GITEA_URL}/api/v1/repos/${REPO}/releases" > release.json
-          RELEASE_ID=$(cat release.json | grep -o '"id":[0-9]*' | head -1 | grep -o '[0-9]*')
+            "${GITEA_URL}/api/v1/repos/${REPO}/releases/tags/${TAG}")
+          case "${HTTP_CODE}" in
+            200)
+              echo "Release ${TAG} already exists, reusing"
+              ;;
+            404)
+              echo "Creating release ${TAG}"
+              curl -fsS -X POST \
+                -H "Authorization: token ${TOKEN}" \
+                -H "Content-Type: application/json" \
+                -d "{\"tag_name\": \"${TAG}\", \"name\": \"Triple-C ${TAG} (Linux)\", \"body\": \"Automated build from commit ${{ gitea.sha }}\"}" \
+                "${GITEA_URL}/api/v1/repos/${REPO}/releases" > release.json
+              ;;
+            *)
+              echo "Unexpected ${HTTP_CODE} looking up release ${TAG}:" >&2
+              cat release.json >&2
+              exit 1
+              ;;
+          esac
+
+          RELEASE_ID=$(python3 -c "import json,sys; print(json.load(open('release.json')).get('id',''))")
+          if [ -z "${RELEASE_ID}" ]; then
+            echo "No release id for ${TAG}; refusing to upload into nothing:" >&2
+            cat release.json >&2
+            exit 1
+          fi
           echo "Release ID: ${RELEASE_ID}"
-          # Upload each artifact
+
+          # Replace-not-conflict, so a retry after a partial upload succeeds.
+          # Versions are monotonic now (see compute-version), so this can only
+          # ever be replacing an asset from a failed run of this same commit —
+          # never one belonging to an already-published version.
           for file in artifacts/*; do
             [ -f "$file" ] || continue
             filename=$(basename "$file")
+
+            EXISTING_ID=$(curl -sS \
+              -H "Authorization: token ${TOKEN}" \
+              "${GITEA_URL}/api/v1/repos/${REPO}/releases/${RELEASE_ID}/assets" \
+              | python3 -c "import json,sys; t=sys.argv[1]; print(next((a['id'] for a in json.load(sys.stdin) if a.get('name')==t), ''))" "${filename}" || true)
+            if [ -n "${EXISTING_ID}" ]; then
+              echo "Deleting existing asset ${filename} (id ${EXISTING_ID})"
+              curl -fsS -X DELETE \
+                -H "Authorization: token ${TOKEN}" \
+                "${GITEA_URL}/api/v1/repos/${REPO}/releases/${RELEASE_ID}/assets/${EXISTING_ID}"
+            fi
+
             echo "Uploading ${filename}..."
-            curl -s -X POST \
+            curl -fsS --http1.1 \
+              --retry 5 --retry-all-errors --retry-delay 5 \
+              --max-time 600 \
+              -X POST \
               -H "Authorization: token ${TOKEN}" \
               -H "Content-Type: application/octet-stream" \
               --data-binary "@${file}" \

CLAUDE.md

@@ -273,6 +273,41 @@ migration and Reset. Four things here are not obvious:
   actively **removes** `triple-c-*.crt` when the setting is cleared — `/usr/local/share` rides the
   project's snapshot image, so turning the feature off has to undo, not merely stop.
 
+### VPN support (`vpn_support_enabled`, `docker/container.rs`)
+
+An opt-in per-project switch granting the container what a VPN client needs to build a tunnel.
+`vpn_host_config()` is the single definition of what that means, and it is unit-tested because a
+container is created once by a very long function where a dropped capability is invisible.
+
+- **All three pieces or none.** `CAP_NET_ADMIN` (Docker's default set has `net_raw` but *not*
+  `net_admin`, so a client can ping but never connect), the `/dev/net/tun` device (absent
+  entirely from a default container — nothing to open even with the capability), and
+  `net.ipv4.conf.all.src_valid_mark=1` (WireGuard's `wg-quick` sets it and cannot from inside a
+  container, since `/proc/sys` is read-only, so handshake packets die to reverse-path filtering).
+  Any two without the third still presents as a connection that hangs to a timeout, which is why
+  the tests assert the whole set.
+- **The device is passed through from the host, never `mknod`-ed inside.** The kernel's `tun`
+  module has to back it.
+- **A missing device fails at `start`, not `create` — verified against Docker 29.7.** `docker
+  create --device /dev/does-not-exist` succeeds and prints an id; runc resolves the device (and
+  validates sysctls) only when it builds the container. So the guard belongs on the start path:
+  `explain_container_failure()` covers both and is called from `start_container`, where it has a
+  container id and no project — which is why it keys off the error naming `/dev/net/tun` rather
+  than off `vpn_support_enabled`. Nothing else in Triple-C requests a device, so that is
+  unambiguous. A version of this check wired to `create` alone is dead code that looks correct.
+- **`NET_ADMIN` here is not user-namespaced.** Docker does not enable userns remapping by default,
+  so only the *network* namespace confines it: no reach onto host interfaces, but promiscuous
+  mode, arbitrary addresses/routes/NAT on the shared `docker0` segment (sibling containers, the
+  LiteLLM gateway among them, are ARP-spoofable), netlink-triggered host module auto-load, and
+  enough authority to flush in-container netfilter rules that sandbox mode may rely on. Keep the
+  code comments honest about this — an earlier draft claimed it "confers no authority" outside the
+  container, which is too strong.
+- **`triple-c.vpn-support` is written unconditionally, including `false`.** The usual
+  `docker commit` reason: a `true` stamped once would ride the snapshot image into every future
+  container and make the switch impossible to turn off.
+- Off is byte-identical to a container created before the feature existed, and a missing label
+  reads as `false`, so no existing project is churned.
+
 ### Container Lifecycle
 
 Containers use a **stop/start** model (not create/destroy). Installed packages persist across stops. The `.claude` config dir uses a named Docker volume (`triple-c-claude-config-{projectId}`), nested inside the home volume (`triple-c-home-{projectId}`), so OAuth tokens and Claude Code config survive container stop/start *and* container recreation.

HOW-TO-USE.md

@@ -471,6 +471,37 @@ When enabled, the host Docker socket is mounted into the container so Claude Cod
 
 > Toggling this requires stopping and restarting the container to take effect.
 
+### VPN Support
+
+When enabled, the container is given the three things a VPN client needs to build a tunnel:
+the `NET_ADMIN` capability, the `/dev/net/tun` device, and the `net.ipv4.conf.all.src_valid_mark`
+sysctl that WireGuard requires. This is **off by default**.
+
+Without it, a client such as PIA, WireGuard or OpenVPN installs and its daemon starts normally, but
+the connection attempt **hangs until it times out** — a default container has no tun device to open
+and no permission to add an interface or a route, and most clients report that as a generic timeout
+rather than a permissions error.
+
+Things worth knowing:
+
+- Tailscale is the exception: in its `--tun=userspace-networking` mode it needs neither the
+  capability nor the device, so leave this off if that is all you want.
+
+- `NET_ADMIN` applies to the container's **own** network namespace — it cannot touch the host's
+  interfaces. It is not nothing, though: within that namespace anything in the container can set
+  promiscuous mode and add arbitrary addresses, routes and firewall rules on the Docker bridge it
+  shares with your other containers, and it can flush firewall rules that sandbox mode relies on.
+  Grant it per project, to projects that need it.
+- The **Docker host's** kernel must have the `tun` module available. With Docker Desktop that is
+  the Linux VM, not your own machine. If it is missing, the container is created but fails to
+  **start**, with an error naming `/dev/net/tun` and pointing back at this setting.
+- A VPN client's kill switch applies to everything in the container, Claude Code included. If the
+  tunnel drops, expect API calls to fail until it reconnects or the kill switch is turned off.
+
+> This setting can only be changed when the container is stopped. Capabilities and devices are
+> fixed when a container is created, so toggling it recreates the container on the next start.
+> Recreation preserves the home and `.claude` volumes — it is not a Reset.
+
 ### Mission Control
 
 Toggle **Mission Control** to integrate Flight Control — an AI-first development methodology bundled with Triple-C — into the project. When enabled:

app/src-tauri/src/browser_view/install.rs

@@ -194,11 +194,24 @@ impl BrowserTarget {
         }
     }
 
-    /// The `channel` a launch check must pass. `None` means the bundled build.
-    fn channel(self) -> Option<&'static str> {
+    /// Every `channel` a launch check must pass, comma-separated, where
+    /// `default` means "no channel — the bundled build".
+    ///
+    /// Chromium is checked twice because the two consumers of this install do
+    /// not launch the same binary. A script calling `chromium.launch()` with
+    /// no channel gets `chromium-headless-shell`; the viewer reads
+    /// `~/.playwright/cli.config.json`, which pins channel
+    /// `chrome-for-testing`, and that resolves to the *full* `chromium-<rev>`
+    /// build — a separate download under the same `install chromium`.
+    ///
+    /// Checking only the first is how a container reaches "verified" and then
+    /// fails in the pane with `Browser "chrome-for-testing" is not installed`.
+    /// Observed on a real project, where a stale `chromium-1217` satisfied the
+    /// headless-shell launch while the viewer wanted `chromium-1237`.
+    fn channels(self) -> &'static str {
         match self {
-            Self::Chromium => None,
-            Self::Chrome => Some("chrome"),
+            Self::Chromium => "default,chrome-for-testing",
+            Self::Chrome => "chrome",
         }
     }
 }
@@ -235,7 +248,7 @@ pub async fn install_packages(
         &format!("Installing @playwright/cli into {}/node_modules…", INSTALL_DIR),
     );
 
-    let mut step = npm_install(app, project_id, container_id, VIEWER_PACKAGE).await?;
+    let mut step = npm_install(app, project_id, container_id, &[VIEWER_PACKAGE]).await?;
     if step.exit_code != 0 {
         return Err(format!(
             "npm couldn't install the viewer package in this container (exit {}).\n\nnpm said:\n{}",
@@ -246,9 +259,15 @@ pub async fn install_packages(
 
     // Second, `playwright` at the version the viewer package pins — see
     // `VIEWER_PACKAGE`. Installing it as `@latest` is what splits the tree.
+    //
+    // The viewer package is named *again* here. It is already installed, so
+    // this adds no work, but omitting it is what made npm prune it back out —
+    // see the note on `npm_install`. The pin can only be read after the first
+    // install has written the manifest, which is why this stays two commands
+    // rather than one.
     let spec = pinned_playwright_spec(container_id).await;
     emit_progress(app, project_id, &format!("Installing {}…", spec));
-    let second = npm_install(app, project_id, container_id, &spec).await?;
+    let second = npm_install(app, project_id, container_id, &[VIEWER_PACKAGE, &spec]).await?;
     if second.exit_code != 0 {
         return Err(format!(
             "npm couldn't install {} in this container (exit {}).\n\nnpm said:\n{}",
@@ -290,7 +309,7 @@ pub async fn install_packages(
     })
 }
 
-/// One `npm install` of one spec, into [`INSTALL_DIR`], as `claude`.
+/// One `npm install` of one or more specs, into [`INSTALL_DIR`], as `claude`.
 ///
 /// `env VAR=… cmd` rather than an exec env: it keeps the one exec path in
 /// `docker/exec.rs` untouched, and `env` is a real binary so no shell is
@@ -298,13 +317,24 @@ pub async fn install_packages(
 /// has no postinstall (verified — `playwright@1.62.1` declares no `scripts` at
 /// all), but if a future release brings the browser download back, this step
 /// must stay small and the download must stay the step the user asked for.
+///
+/// **Every package that must survive has to appear in `specs`.** `--no-save`
+/// in a directory with no `package.json` — which [`INSTALL_DIR`] is — leaves
+/// npm with the command line as its only statement of what the tree should
+/// contain, and npm ≥7 reconciles the tree against that on every run by
+/// removing whatever it now considers extraneous. Installing `@playwright/cli`
+/// and then installing `playwright` in a second command therefore *deletes the
+/// first one*: verified in a container, `removed 3 packages`, leaving an empty
+/// `node_modules/@playwright/` behind `playwright` and `playwright-core`. That
+/// empty directory is why a fresh setup could report success and still leave
+/// the pane saying `@playwright/cli` was not installed.
 async fn npm_install(
     app: &AppHandle,
     project_id: &str,
     container_id: &str,
-    spec: &str,
+    specs: &[&str],
 ) -> Result<StepResult, String> {
-    let cmd = vec![
+    let mut cmd = vec![
         "env".to_string(),
         "PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1".to_string(),
         "npm".to_string(),
@@ -313,8 +343,8 @@ async fn npm_install(
         "--no-save".to_string(),
         "--no-fund".to_string(),
         "--no-audit".to_string(),
-        spec.to_string(),
     ];
+    cmd.extend(specs.iter().map(|s| s.to_string()));
     run_step(
         app,
         project_id,
@@ -704,7 +734,7 @@ async fn verify_launch(
         ],
         vec![
             format!("TRIPLE_C_PW_DIR={}", dir),
-            format!("TRIPLE_C_PW_CHANNEL={}", target.channel().unwrap_or("")),
+            format!("TRIPLE_C_PW_CHANNELS={}", target.channels()),
             format!("TRIPLE_C_PW_URL={}", REACHABILITY_URL),
         ],
     );
@@ -795,27 +825,43 @@ fn parse_launch_output(output: &str) -> LaunchVerdict {
 /// The launch check. One `argv` element, no newlines, same contract as the
 /// detection probe.
 ///
-/// Playwright leaves the Chromium sandbox disabled by default, which is what
-/// makes this work in a container at all. The timeout exists so a browser that
-/// hangs on a missing library still returns a verdict rather than sitting there
-/// until the exec is torn down. The navigation is best-effort and never decides
-/// `ok` — it exists to tell a TLS-intercepted network apart from a broken
-/// install.
+/// `chromiumSandbox` is set explicitly rather than left to Playwright's
+/// default, so this check states the same thing the seeded
+/// `cli.config.json` does instead of agreeing with it by coincidence. The
+/// containers forbid unprivileged user namespaces, so a sandboxed Chromium
+/// aborts on launch; nothing here should be able to drift back into testing a
+/// configuration the viewer will not use.
+///
+/// Each channel in `TRIPLE_C_PW_CHANNELS` is launched in turn — see
+/// [`BrowserTarget::channels`] for why Chromium needs two — and a failure
+/// names the channel that failed, because "is not installed" is meaningless
+/// without it. Only the last launch loads a page: the navigation is
+/// best-effort, never decides `ok`, and exists to tell a TLS-intercepted
+/// network apart from a broken install, so doing it once is enough.
+///
+/// The timeout exists so a browser that hangs on a missing library still
+/// returns a verdict rather than sitting there until the exec is torn down.
 const LAUNCH_PROBE: &str = concat!(
-    r#"const d=process.env.TRIPLE_C_PW_DIR,ch=process.env.TRIPLE_C_PW_CHANNEL||undefined,u=process.env.TRIPLE_C_PW_URL;"#,
+    r#"const d=process.env.TRIPLE_C_PW_DIR,chs=process.env.TRIPLE_C_PW_CHANNELS||"default",u=process.env.TRIPLE_C_PW_URL;"#,
     r#"let done=false;const say=(ok,detail,nav)=>{if(done)return;done=true;"#,
     r#"process.stdout.write("\n__TRIPLE_C_BROWSER_LAUNCH__"+JSON.stringify({ok,detail,nav:nav||null})+"\n");};"#,
     r#"const one=(e)=>String((e&&e.message)||e).split("\n").slice(0,8).join(" | ");"#,
     r#"const t=setTimeout(()=>{say(false,"the browser did not finish starting within 90s");process.exit(0);},90000);"#,
-    r#"(async()=>{let b=null;try{const {chromium}=require(d);b=await chromium.launch(ch?{channel:ch}:{});"#,
-    r#"let v="";try{v=b.version();}catch(e){}"#,
-    r#"let nav={ok:true,cert:false,detail:""};"#,
+    r#"(async()=>{let b=null,cur="";try{const {chromium}=require(d);"#,
+    r#"const list=chs.split(",").map(s=>s.trim()).filter(Boolean);"#,
+    r#"let v="",nav={ok:true,cert:false,detail:""};"#,
+    r#"for(let i=0;i<list.length;i++){cur=list[i];const c=cur==="default"?undefined:cur;"#,
+    r#"b=await chromium.launch(Object.assign({chromiumSandbox:false},c?{channel:c}:{}));"#,
+    r#"try{v=b.version();}catch(e){}"#,
+    r#"if(i===list.length-1){"#,
     r#"try{const p=await b.newPage();await p.goto(u,{timeout:20000});}"#,
     // A certificate failure is classified here, next to the message, because
     // Chromium's wording is the only place the distinction exists.
-    r#"catch(e){const m=one(e);nav={ok:false,cert:/ERR_CERT|CERT_AUTHORITY|ERR_SSL|SSL_ERROR|self.signed/i.test(m),detail:m};}"#,
-    r#"await b.close();clearTimeout(t);say(true,v,nav);}"#,
-    r#"catch(e){clearTimeout(t);try{if(b)await b.close();}catch(e2){}say(false,one(e));}"#,
+    r#"catch(e){const m=one(e);nav={ok:false,cert:/ERR_CERT|CERT_AUTHORITY|ERR_SSL|SSL_ERROR|self.signed/i.test(m),detail:m};}}"#,
+    r#"await b.close();b=null;}"#,
+    r#"clearTimeout(t);say(true,v,nav);}"#,
+    r#"catch(e){clearTimeout(t);try{if(b)await b.close();}catch(e2){}"#,
+    r#"say(false,(cur&&cur!=="default"?"channel "+cur+": ":"")+one(e));}"#,
     r#"process.exit(0);})();"#,
 );
 
@@ -984,8 +1030,10 @@ mod tests {
         // `@playwright/mcp` asks for the chrome channel specifically, so the UI
         // must be able to say so.
         assert!(BrowserTarget::Chrome.needed_for().contains("@playwright/mcp"));
-        assert_eq!(BrowserTarget::Chrome.channel(), Some("chrome"));
-        assert_eq!(BrowserTarget::Chromium.channel(), None);
+        assert_eq!(BrowserTarget::Chrome.channels(), "chrome");
+        // Both of Chromium's consumers, or the check passes for a browser the
+        // viewer cannot open — see `channels`.
+        assert_eq!(BrowserTarget::Chromium.channels(), "default,chrome-for-testing");
         // And a size, before the click, for both.
         for t in [BrowserTarget::Chromium, BrowserTarget::Chrome] {
             assert!(t.download_note().to_lowercase().contains("mb"), "{:?}", t);

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

@@ -73,6 +73,25 @@ use crate::AppState;
 /// Report how far behind the current base image a project's container is, and
 /// what migrating it would actually carry across.
 ///
+/// Choose the recorded lineage from the two places it can be written, most
+/// authoritative first: the live container's label, then the snapshot image's.
+///
+/// **An empty label is absence, not an answer.** `create_container` always
+/// writes `triple-c.base-image-id`, even when the value is unknown — that is
+/// deliberate, because Docker merges an image's labels into a container's and
+/// an inherited value would otherwise ride a snapshot forever. The consequence
+/// is that `Some("")` is the *common* reading from a container whose lineage
+/// was never established, so treating it as an answer silently skips the
+/// snapshot, which may well have recorded a real one.
+fn pick_recorded_lineage(
+    from_container: Option<String>,
+    from_snapshot: Option<String>,
+) -> Option<String> {
+    from_container
+        .filter(|v| !v.is_empty())
+        .or_else(|| from_snapshot.filter(|v| !v.is_empty()))
+}
+
 /// Read-only. Runs two filesystem probes (~3 s each) and is therefore meant to
 /// be called on demand, not polled.
 #[tauri::command]
@@ -98,20 +117,24 @@ pub async fn get_container_staleness(
     // Lineage, most authoritative source first: the live container's label,
     // then the snapshot image's. Both are written by `create_container` and
     // propagated onto the snapshot by `docker commit`.
+    // Each source is filtered for emptiness *before* it is allowed to satisfy
+    // the lookup. `create_container` always writes this label, even when the
+    // value is unknown — deliberately, so an inherited image label cannot ride
+    // a snapshot forever — which means the container's copy is very often
+    // `Some("")`. Filtering only the final result let that empty string count
+    // as an answer and skip the snapshot entirely, so a snapshot that *did*
+    // record a lineage was never consulted and the project reported "unknown"
+    // with the information sitting one lookup away.
     let container_id = docker::find_existing_container(&project).await.unwrap_or(None);
-    let recorded = match &container_id {
+    let from_container = match &container_id {
         Some(id) => container_label(id, mig::LABEL_BASE_IMAGE_ID).await,
         None => None,
-    }
-    .or_else(|| None);
-    let recorded = match recorded {
-        Some(v) => Some(v),
-        None => mig::image_labels(&snapshot_image)
-            .await
-            .get(mig::LABEL_BASE_IMAGE_ID)
-            .cloned(),
-    }
-    .filter(|v| !v.is_empty());
+    };
+    let from_snapshot = mig::image_labels(&snapshot_image)
+        .await
+        .get(mig::LABEL_BASE_IMAGE_ID)
+        .cloned();
+    let recorded = pick_recorded_lineage(from_container, from_snapshot);
 
     out.base_image_id = recorded.clone();
     out.known = recorded.is_some();
@@ -1671,6 +1694,32 @@ fn summarize(
 mod tests {
     use super::*;
 
+    #[test]
+    fn an_empty_lineage_label_is_absence_and_falls_through_to_the_snapshot() {
+        let some = |s: &str| Some(s.to_string());
+
+        // The regression: the container always carries the label, so an
+        // unknown lineage reads as `Some("")`. Letting that satisfy the lookup
+        // skipped a snapshot that had recorded the real thing.
+        assert_eq!(
+            pick_recorded_lineage(some(""), some("sha256:base")),
+            some("sha256:base")
+        );
+
+        // Ordinary precedence still holds: the container wins when it has one.
+        assert_eq!(
+            pick_recorded_lineage(some("sha256:container"), some("sha256:snapshot")),
+            some("sha256:container")
+        );
+        assert_eq!(pick_recorded_lineage(None, some("sha256:snap")), some("sha256:snap"));
+
+        // Genuinely unknown stays unknown — "probe instead", never a lineage
+        // invented to make the comparison succeed.
+        assert_eq!(pick_recorded_lineage(None, None), None);
+        assert_eq!(pick_recorded_lineage(some(""), some("")), None);
+        assert_eq!(pick_recorded_lineage(some(""), None), None);
+    }
+
     #[test]
     fn byte_sizes_read_the_way_a_disk_warning_should() {
         assert_eq!(human_bytes(512), "512 B");

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

@@ -798,6 +798,111 @@ async fn resolve_base_image_id(image_name: &str, base_image_name: &str) -> Strin
         .unwrap_or_default()
 }
 
+/// The `/dev/net/tun` character device, as it is named on both sides.
+const TUN_DEVICE: &str = "/dev/net/tun";
+
+/// The `HostConfig` fields "VPN support" contributes: `CapAdd`, `Devices`,
+/// `Sysctls` — in that order.
+type VpnHostConfigParts = (
+    Option<Vec<String>>,
+    Option<Vec<bollard::models::DeviceMapping>>,
+    Option<HashMap<String, String>>,
+);
+
+/// The three host-config pieces a VPN client needs, or all-`None` when the
+/// project has not opted in.
+///
+/// Returned as a triple rather than set inline so the exact shape is unit
+/// testable — a container is created once, by a very long async function, and a
+/// silently-dropped capability looks identical to a VPN server that is simply
+/// unreachable.
+///
+/// All three are required together and each fails differently on its own:
+/// * **`CAP_NET_ADMIN`** — without it the client cannot create an interface or
+///   write a route. Docker's default bounding set grants `net_raw` but not
+///   `net_admin`, which is why a client can ping but never connect.
+/// * **`/dev/net/tun`** — the device is absent from a default container, so
+///   there is nothing to open even with the capability. It is passed through
+///   from the host rather than `mknod`-ed inside, so the kernel's `tun` module
+///   backs it.
+/// * **`net.ipv4.conf.all.src_valid_mark`** — WireGuard's own `wg-quick` sets
+///   this, and cannot from inside a container (`/proc/sys` is read-only), so
+///   its handshake packets are dropped by reverse-path filtering. Harmless for
+///   OpenVPN-based clients, so it is set unconditionally with the rest.
+///
+/// What it costs, stated accurately: Docker does not enable user-namespace
+/// remapping by default, so this is a real `CAP_NET_ADMIN` in the *initial*
+/// user namespace and only the **network** namespace confines it. It cannot
+/// touch the host's interfaces, but within its own namespace it can set
+/// promiscuous mode and add arbitrary addresses, routes and NAT rules on the
+/// shared `docker0` L2 segment — which puts sibling containers (the LiteLLM
+/// gateway among them) within reach of ARP spoofing, and lets netlink trigger
+/// host-kernel module auto-loading. It is also enough to flush netfilter rules
+/// inside the container, so pair it with `sandbox_mode_enabled` advisedly.
+/// Hence opt-in, per project, rather than on for everyone.
+fn vpn_host_config(enabled: bool) -> VpnHostConfigParts {
+    if !enabled {
+        return (None, None, None);
+    }
+
+    let devices = vec![bollard::models::DeviceMapping {
+        path_on_host: Some(TUN_DEVICE.to_string()),
+        path_in_container: Some(TUN_DEVICE.to_string()),
+        cgroup_permissions: Some("rwm".to_string()),
+    }];
+
+    let sysctls = HashMap::from([(
+        "net.ipv4.conf.all.src_valid_mark".to_string(),
+        "1".to_string(),
+    )]);
+
+    (
+        Some(vec!["NET_ADMIN".to_string()]),
+        Some(devices),
+        Some(sysctls),
+    )
+}
+
+/// Turn the daemon's device-passthrough failure into an explanation.
+///
+/// **This fires on `start`, not `create`.** Verified against Docker 29.7:
+/// `docker create --device /dev/does-not-exist` succeeds and prints an id; the
+/// device is only resolved when runc builds the container, so the failure lands
+/// on the *next* call. Sysctls validate at the same point. Anything that
+/// inspects only the create path will never see it — which is why both paths
+/// route through here and the tests exercise the start-side string.
+///
+/// Unmapped, this reads as `Failed to start container: Docker responded with
+/// status code 500: error gathering device information while adding custom
+/// device "/dev/net/tun": no such file or directory` — a path the user will go
+/// looking for on the wrong machine, since with Docker Desktop the relevant
+/// host is the Linux VM rather than their own, and with nothing pointing back
+/// at the switch that caused it.
+///
+/// Deliberately not gated on `vpn_support_enabled`: nothing else in Triple-C
+/// ever asks for a device, so an error naming `/dev/net/tun` can only have come
+/// from a container created with the switch on. That keeps the check usable
+/// from [`start_container`], which has a container id and no project.
+fn explain_container_failure(action: &str, err: &str) -> String {
+    let device_missing = err.contains(TUN_DEVICE)
+        && (err.contains("no such file or directory")
+            || err.contains("No such file or directory")
+            || err.contains("error gathering device information"));
+
+    if device_missing {
+        return format!(
+            "Failed to {} container: the Docker host has no {} device, which \
+             \"VPN support\" requires. The host kernel needs the `tun` module \
+             loaded (on Docker Desktop that is the Linux VM, not your own \
+             machine). Turn VPN support off in Config → Runtime to start this \
+             project without it. Original error: {}",
+            action, TUN_DEVICE, err
+        );
+    }
+
+    format!("Failed to {} container: {}", action, err)
+}
+
 pub async fn create_container(
     project: &Project,
     docker_socket_path: &str,
@@ -1375,6 +1480,13 @@ pub async fn create_container(
     labels.insert("triple-c.image".to_string(), image_name.to_string());
     labels.insert("triple-c.timezone".to_string(), timezone.unwrap_or("").to_string());
     labels.insert("triple-c.mission-control".to_string(), project.mission_control_enabled.to_string());
+    // Capabilities, devices and sysctls are fixed at creation, so this is
+    // container state and gets the label-and-compare treatment. Written
+    // unconditionally (`false`, not omitted) because `docker commit` copies
+    // container labels onto the snapshot image: a `true` stamped once would
+    // otherwise ride that snapshot into every future container and make the
+    // switch impossible to turn back off.
+    labels.insert("triple-c.vpn-support".to_string(), project.vpn_support_enabled.to_string());
     labels.insert("triple-c.permission-mode".to_string(),
         project.effective_permission_mode().as_env_value().to_string());
     labels.insert("triple-c.custom-env-fingerprint".to_string(), custom_env_fingerprint.clone());
@@ -1443,10 +1555,15 @@ pub async fn create_container(
         labels.insert((*key).to_string(), (*value).to_string());
     }
 
+    let (cap_add, devices, sysctls) = vpn_host_config(project.vpn_support_enabled);
+
     let host_config = HostConfig {
         mounts: Some(mounts),
         port_bindings: if port_bindings.is_empty() { None } else { Some(port_bindings) },
         init: Some(true),
+        cap_add,
+        devices,
+        sysctls,
         ..Default::default()
     };
 
@@ -1476,7 +1593,7 @@ pub async fn create_container(
     let response = docker
         .create_container(Some(options), config)
         .await
-        .map_err(|e| format!("Failed to create container: {}", e))?;
+        .map_err(|e| explain_container_failure("create", &e.to_string()))?;
 
     Ok(response.id)
 }
@@ -1486,7 +1603,7 @@ pub async fn start_container(container_id: &str) -> Result<(), String> {
     docker
         .start_container(container_id, None::<StartContainerOptions<String>>)
         .await
-        .map_err(|e| format!("Failed to start container: {}", e))
+        .map_err(|e| explain_container_failure("start", &e.to_string()))
 }
 
 pub async fn stop_container(container_id: &str) -> Result<(), String> {
@@ -2367,6 +2484,19 @@ pub async fn container_needs_recreation(
         return Ok(true);
     }
 
+    // ── VPN support (NET_ADMIN + /dev/net/tun + sysctl) ───────────────────
+    // A container's capabilities, devices and sysctls are set at creation and
+    // cannot be changed on a running or stopped container, so recreation is the
+    // only way a toggle here takes effect. A missing label means the container
+    // predates the feature, which is the same thing as having it off — so
+    // existing projects are not churned until someone actually turns it on.
+    let expected_vpn = project.vpn_support_enabled.to_string();
+    let container_vpn = get_label("triple-c.vpn-support").unwrap_or_else(|| "false".to_string());
+    if container_vpn != expected_vpn {
+        log::info!("VPN support mismatch (container={:?}, expected={:?})", container_vpn, expected_vpn);
+        return Ok(true);
+    }
+
     // ── Permission mode ────────────────────────────────────────────────────
     // The mode is injected as the TRIPLE_C_PERMISSION_MODE env var, and
     // container env can only change by recreating the container. A missing
@@ -2616,6 +2746,98 @@ mod tests {
         assert_eq!(fp, "");
     }
 
+    #[test]
+    fn vpn_support_off_touches_nothing_in_the_host_config() {
+        // The default must stay byte-identical to a container created before the
+        // feature existed, or every project recreates on the next start.
+        let (cap_add, devices, sysctls) = vpn_host_config(false);
+        assert_eq!(cap_add, None);
+        assert_eq!(devices, None);
+        assert_eq!(sysctls, None);
+    }
+
+    #[test]
+    fn vpn_support_on_grants_all_three_pieces() {
+        // Each is useless without the others — a client with the capability but
+        // no device, or the device but no capability, still times out — so this
+        // asserts the whole set rather than any one of them.
+        let (cap_add, devices, sysctls) = vpn_host_config(true);
+
+        assert_eq!(cap_add, Some(vec!["NET_ADMIN".to_string()]));
+
+        let devices = devices.expect("the tun device must be passed through");
+        assert_eq!(devices.len(), 1);
+        assert_eq!(devices[0].path_on_host.as_deref(), Some(TUN_DEVICE));
+        assert_eq!(devices[0].path_in_container.as_deref(), Some(TUN_DEVICE));
+        assert_eq!(devices[0].cgroup_permissions.as_deref(), Some("rwm"));
+
+        assert_eq!(
+            sysctls
+                .expect("wireguard needs src_valid_mark")
+                .get("net.ipv4.conf.all.src_valid_mark")
+                .map(String::as_str),
+            Some("1")
+        );
+    }
+
+    #[test]
+    fn vpn_support_never_grants_more_than_net_admin() {
+        // NET_ADMIN is already a step out of the sandbox. Anything else added
+        // here (SYS_ADMIN, or a blanket privileged flag) would be a much larger
+        // one, so pin the set.
+        let (cap_add, _, _) = vpn_host_config(true);
+        assert_eq!(cap_add.unwrap(), vec!["NET_ADMIN"]);
+    }
+
+    /// What bollard actually hands us when a tun-less host rejects the device.
+    ///
+    /// Captured verbatim from Docker 29.7: `docker create` with a missing
+    /// device **succeeds**, and this arrives from the subsequent `start`.
+    /// `DockerResponseServerError`'s Display is
+    /// `"Docker responded with status code {code}: {message}"` with the
+    /// daemon's message unaltered.
+    const REAL_TUN_ERROR: &str = "Docker responded with status code 500: error \
+        gathering device information while adding custom device \
+        \"/dev/net/tun\": no such file or directory";
+
+    #[test]
+    fn a_missing_tun_device_is_explained_on_the_path_that_actually_fails() {
+        // The start path is the one that matters: the daemon defers device
+        // resolution to runc, so create returns an id on a host with no tun
+        // module and only start fails. A version of this that checked create
+        // alone would be dead code.
+        let msg = explain_container_failure("start", REAL_TUN_ERROR);
+        assert!(msg.starts_with("Failed to start container:"), "{}", msg);
+        assert!(msg.contains("VPN support"), "should name the switch: {}", msg);
+        assert!(msg.contains("tun` module"), "should name the cause: {}", msg);
+        assert!(msg.contains("Config → Runtime"), "should say where to fix it: {}", msg);
+        assert!(msg.contains(REAL_TUN_ERROR), "should keep the original: {}", msg);
+    }
+
+    #[test]
+    fn the_same_explanation_covers_create_if_the_daemon_ever_checks_earlier() {
+        // Belt and braces — older and future daemons may validate at create.
+        let msg = explain_container_failure("create", REAL_TUN_ERROR);
+        assert!(msg.starts_with("Failed to create container:"), "{}", msg);
+        assert!(msg.contains("VPN support"), "{}", msg);
+    }
+
+    #[test]
+    fn unrelated_failures_are_left_alone() {
+        for (action, err) in [
+            ("create", "Conflict. The container name \"/triple-c-x\" is already in use"),
+            ("start", "Docker responded with status code 404: No such container"),
+            ("start", "error gathering device information while adding custom device \"/dev/dri/card0\""),
+        ] {
+            assert_eq!(
+                explain_container_failure(action, err),
+                format!("Failed to {} container: {}", action, err),
+                "{} should pass through untouched",
+                err
+            );
+        }
+    }
+
     #[test]
     fn the_orphan_sweep_only_ever_looks_at_our_own_untagged_images() {
         // Both conditions are load-bearing. Without `dangling` the sweep would

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

@@ -145,6 +145,22 @@ pub struct Project {
     /// container-recreation label.
     #[serde(default)]
     pub browser_view_enabled: bool,
+    /// Grant the container what a VPN client needs to build a tunnel:
+    /// `CAP_NET_ADMIN`, the `/dev/net/tun` device, and the WireGuard
+    /// `src_valid_mark` sysctl. Without all three a client (PIA, WireGuard,
+    /// OpenVPN) installs and runs but its connection attempt hangs until it
+    /// times out, because it cannot create the tunnel interface or touch the
+    /// routing table.
+    ///
+    /// Off by default and deliberately opt-in: `NET_ADMIN` lets anything in the
+    /// container reconfigure its own network stack, which reaches further than
+    /// it sounds — see `vpn_host_config` for what it does and does not confer.
+    /// Unlike `auth_bridge_enabled` this *is*
+    /// container state, so it carries a `triple-c.vpn-support` label and is
+    /// compared in `container_needs_recreation` — capabilities and devices are
+    /// fixed at creation and can only change by recreating the container.
+    #[serde(default)]
+    pub vpn_support_enabled: bool,
     /// Use the shared, long-lived Claude Code OAuth token (from
     /// `claude setup-token`, held in the OS keychain) for this project instead
     /// of requiring its own `claude login`. Only consulted when `backend` is
@@ -366,6 +382,7 @@ impl Project {
             mission_control_enabled: false,
             auth_bridge_enabled: false,
             browser_view_enabled: false,
+            vpn_support_enabled: false,
             use_shared_auth_token: default_use_shared_auth_token(),
             full_permissions: false,
             permission_mode: None,

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

@@ -127,6 +127,46 @@ describe("ContainerMigrationBanner", () => {
     expect(container).toBeEmptyDOMElement();
   });
 
+  it("speaks up when an unlabelled container could not be probed at all", () => {
+    // The probe is the only signal a container with no lineage label has. If
+    // it fails and the banner stays silent, that is indistinguishable from
+    // "up to date" — the exact reading that let an out-of-date project go
+    // unnoticed indefinitely.
+    renderBanner(
+      migration({
+        staleness: {
+          ...FRESH,
+          known: false,
+          stale: false,
+          probe_error: "output exceeded the inspection limit",
+        },
+        probeSettled: false,
+      }),
+    );
+    expect(
+      screen.getByText(/Container base could not be checked/i),
+    ).toBeInTheDocument();
+    expect(
+      screen.getByText(/output exceeded the inspection limit/i),
+    ).toBeInTheDocument();
+    // And it must not pose as a finding about the container itself.
+    expect(
+      screen.queryByText(/Container is missing things/i),
+    ).not.toBeInTheDocument();
+  });
+
+  it("stays quiet when a labelled container's probe fails but its lineage is current", () => {
+    // `known` means the version comparison already answered the question, so
+    // a failed probe is not grounds to raise anything.
+    const { container } = renderBanner(
+      migration({
+        staleness: { ...FRESH, probe_error: "could not exec in the container" },
+        probeSettled: false,
+      }),
+    );
+    expect(container).toBeEmptyDOMElement();
+  });
+
   it("disables the action and explains why while the container is running", () => {
     renderBanner(migration({ staleness: STALE }), false);
     expect(

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

@@ -131,7 +131,15 @@ export default function ContainerMigrationBanner({
   const probeFoundGaps =
     !staleness.known &&
     (staleness.missing_features.length > 0 || staleness.missing_paths.length > 0);
-  if (!staleness.stale && !probeFoundGaps) return null;
+
+  // The probe is the *only* signal a container with no lineage label has, so
+  // when it fails there is nothing left to be quiet about. Staying silent here
+  // is indistinguishable from "everything is fine" — and it is the likeliest
+  // outcome for the oldest, largest projects, whose manifests are the ones apt
+  // to exceed the inspection limit. Say that the check did not run instead.
+  const probeUnavailable = !staleness.known && !!staleness.probe_error;
+
+  if (!staleness.stale && !probeFoundGaps && !probeUnavailable) return null;
 
   const snapshot = formatSnapshotDate(staleness.snapshot_created_at);
   const features = joinFeatures(staleness.missing_features);
@@ -139,16 +147,25 @@ export default function ContainerMigrationBanner({
   return (
     <section
       className={`${SHELL} border-[var(--warning)]/40 bg-[var(--warning-muted)]`}
-      aria-label="Container base is out of date"
+      aria-label={
+        probeUnavailable
+          ? "Container base could not be checked"
+          : "Container base is out of date"
+      }
     >
       <div className="flex items-start justify-between gap-3">
         <div className="min-w-0 space-y-1">
           <StatusIndicator
-            tone="error"
+            // A check that could not run is not a finding: it gets the
+            // "unresolved" tone rather than the one that says something is
+            // wrong with the container.
+            tone={probeUnavailable ? "unknown" : "error"}
             label={
               staleness.known
                 ? "Container base is out of date"
-                : "Container is missing things the current base ships"
+                : probeUnavailable
+                  ? "Container base could not be checked"
+                  : "Container is missing things the current base ships"
             }
             className="text-[13px] font-semibold"
           />
@@ -158,7 +175,9 @@ export default function ContainerMigrationBanner({
               ? snapshot
                 ? `Running on a saved image from ${snapshot}.`
                 : "Running on a saved image older than the current base."
-              : "This container predates base-image tracking, so it was probed directly."}
+              : probeUnavailable
+                ? "This container predates base-image tracking, so probing it is the only way to tell whether it is behind — and that did not complete."
+                : "This container predates base-image tracking, so it was probed directly."}
           </p>
 
           {staleness.missing_features.length > 0 && (

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

@@ -120,6 +120,15 @@ export default function OverviewTab({
               {project.mission_control_enabled ? "ON" : "OFF"}
             </span>
           </span>
+          {/* Only when granted. It is off for nearly every project and an
+              always-present "VPN OFF" would be noise, but where it *is* on the
+              container holds NET_ADMIN, which is worth seeing at a glance. */}
+          {project.vpn_support_enabled && (
+            <span className="text-[var(--text-secondary)]">
+              VPN support{" "}
+              <span className="text-[var(--text-primary)] font-medium">ON</span>
+            </span>
+          )}
           <button
             type="button"
             onClick={() => onOpenTab("config")}

app/src/components/projects/home/config/RuntimeSection.test.tsx

@@ -0,0 +1,94 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent } from "@testing-library/react";
+import RuntimeSection from "./RuntimeSection";
+import type { Project } from "../../../../lib/types";
+
+const baseProject: Project = {
+  id: "p1",
+  name: "api-server",
+  paths: [{ host_path: "/src/api", mount_name: "api" }],
+  container_id: null,
+  status: "stopped",
+  backend: "anthropic",
+  bedrock_config: null,
+  ollama_config: null,
+  llamacpp_config: null,
+  openai_compatible_config: null,
+  allow_docker_access: false,
+  sandbox_mode_enabled: true,
+  mission_control_enabled: false,
+  auth_bridge_enabled: false,
+  browser_view_enabled: false,
+  vpn_support_enabled: false,
+  use_shared_auth_token: true,
+  full_permissions: false,
+  permission_mode: null,
+  ssh_key_path: null,
+  ca_cert_path: null,
+  git_token: null,
+  git_user_name: null,
+  git_user_email: null,
+  custom_env_vars: [],
+  port_mappings: [],
+  claude_instructions: null,
+  claude_code_settings: null,
+  renamed_session_names: {},
+  created_at: "2026-01-01T00:00:00Z",
+  updated_at: "2026-01-01T00:00:00Z",
+};
+
+const VPN = "VPN support";
+
+const save = vi.fn().mockResolvedValue(true);
+
+function renderSection(over: Partial<Project> = {}, disabled = false) {
+  return render(
+    <RuntimeSection
+      project={{ ...baseProject, ...over }}
+      save={save}
+      disabled={disabled}
+      disabledReason="Container must be stopped to change this setting."
+    />,
+  );
+}
+
+describe("RuntimeSection — VPN support toggle", () => {
+  beforeEach(() => vi.clearAllMocks());
+
+  it("saves only the VPN flag when switched on", () => {
+    renderSection();
+    fireEvent.click(screen.getByRole("switch", { name: VPN }));
+    expect(save).toHaveBeenCalledWith({ vpn_support_enabled: true });
+  });
+
+  it("saves the flag off again, rather than dropping the key", () => {
+    // Off has to be written explicitly: the container carries a
+    // `triple-c.vpn-support` label either way, and an absent value would leave
+    // the capability granted.
+    renderSection({ vpn_support_enabled: true });
+    fireEvent.click(screen.getByRole("switch", { name: VPN }));
+    expect(save).toHaveBeenCalledWith({ vpn_support_enabled: false });
+  });
+
+  it("reflects the project's current state", () => {
+    renderSection({ vpn_support_enabled: true });
+    expect(screen.getByRole("switch", { name: VPN })).toBeChecked();
+  });
+
+  it("cannot be changed while the container is running", () => {
+    // Capabilities and devices are fixed at creation, so this setting is gated
+    // on the container being stopped along with the rest of the tab.
+    renderSection({}, true);
+    const toggle = screen.getByRole("switch", { name: VPN });
+    expect(toggle).toBeDisabled();
+    fireEvent.click(toggle);
+    expect(save).not.toHaveBeenCalled();
+  });
+
+  it("warns that the change recreates the container", () => {
+    renderSection();
+    expect(
+      screen.getByText(/recreates the container on its next start/i),
+    ).toBeInTheDocument();
+  });
+});

app/src/components/projects/home/config/RuntimeSection.tsx

@@ -57,6 +57,19 @@ export default function RuntimeSection({
           }
         />
 
+        <SwitchRow
+          label="VPN support"
+          hint="Grants NET_ADMIN and the /dev/net/tun device so a VPN client (PIA, WireGuard, OpenVPN) can build a tunnel inside the container. Without it a client installs and runs but its connection hangs until it times out. Anything in the container can then reconfigure the container's own network stack; the host's is untouched. Changing this recreates the container on its next start — the home and .claude volumes are preserved."
+          control={
+            <Toggle
+              label="VPN support"
+              checked={project.vpn_support_enabled}
+              disabled={disabled}
+              onChange={(v) => save({ vpn_support_enabled: v })}
+            />
+          }
+        />
+
         <SwitchRow
           label="Mission Control"
           hint="A web dashboard for monitoring and managing Claude sessions remotely."

app/src/lib/types.ts

@@ -33,6 +33,10 @@ export interface Project {
   auth_bridge_enabled: boolean;
   /** Opt in to the browser-view pane. Host-side only, like `auth_bridge_enabled`. */
   browser_view_enabled: boolean;
+  /** Grant NET_ADMIN, /dev/net/tun and the WireGuard `src_valid_mark` sysctl so
+   *  a VPN client inside the container can build a tunnel. Unlike the two flags
+   *  above this is container state — changing it recreates the container. */
+  vpn_support_enabled: boolean;
   /** Use the shared long-lived Claude Code token (from `claude setup-token`,
    *  held in the OS keychain) instead of this project's own `claude login`.
    *  Defaults to true; only applies when `backend` is "anthropic" and a token

container/Dockerfile

@@ -318,6 +318,13 @@ COPY entrypoint.sh /usr/local/bin/entrypoint.sh
 RUN chmod +x /usr/local/bin/entrypoint.sh
 COPY triple-c-scheduler /usr/local/bin/triple-c-scheduler
 RUN chmod +x /usr/local/bin/triple-c-scheduler
+# Lives in /usr/local/bin rather than under /home/claude on purpose: the home
+# directory is the mount point of the project's home volume, so an image copy
+# of it is masked after the project's first start and can never be updated
+# again. /usr/local/bin rides the snapshot and is replaced on migration, which
+# is what lets a fix to this script reach an existing project at all.
+COPY triple-c-playwright-heal /usr/local/bin/triple-c-playwright-heal
+RUN chmod +x /usr/local/bin/triple-c-playwright-heal
 COPY triple-c-task-runner /usr/local/bin/triple-c-task-runner
 RUN chmod +x /usr/local/bin/triple-c-task-runner
 

container/entrypoint.sh

@@ -425,6 +425,32 @@ if [ -x /usr/local/bin/triple-c-open ]; then
     export BROWSER=/usr/local/bin/triple-c-open
 fi
 
+# ── Playwright browser config ───────────────────────────────────────────────
+# Seed ~/.playwright/cli.config.json on every start.
+#
+# Without it `playwright-cli` resolves to channel `chrome` — system Google
+# Chrome — with the Chromium sandbox ON, and these containers do not permit
+# unprivileged user namespaces, so the browser aborts with "Failed to move to
+# new namespace ... Operation not permitted". On a base image that no longer
+# ships Google Chrome the same default fails the other way, with "Chromium
+# distribution 'chrome' is not found". One cause, two error messages, and
+# neither of them looks like a configuration problem.
+#
+# Seeded here rather than baked into the image because ~/.playwright is inside
+# the home volume: an image copy would reach new projects only, and every
+# existing project would stay broken forever. Written on every start from a
+# source outside the volume, the way CLAUDE_INSTRUCTIONS and the Mission
+# Control skills already are.
+#
+# --seed-config-only is the cheap path: no npm install, no browser download, no
+# apt, no verify launch, nothing over the network. It writes one small file if
+# it is absent and returns. Measured at ~2 ms. The heavier repairs stay
+# on-demand — run `triple-c-playwright-heal` with no arguments for those.
+if [ -x /usr/local/bin/triple-c-playwright-heal ]; then
+    /usr/local/bin/triple-c-playwright-heal --seed-config-only --quiet || \
+        echo "entrypoint: warning — playwright config seeding failed (browser view may not launch)"
+fi
+
 # ── Scheduler setup ─────────────────────────────────────────────────────────
 SCHEDULER_DIR="/home/claude/.claude/scheduler"
 mkdir -p "$SCHEDULER_DIR/tasks" "$SCHEDULER_DIR/logs" "$SCHEDULER_DIR/notifications"

container/triple-c-playwright-heal

@@ -0,0 +1,272 @@
+#!/bin/bash
+# triple-c-playwright-heal — make Playwright usable in a Triple-C container.
+#
+# Idempotent: safe to run on every start and safe to re-run after a partial
+# failure. Each step checks for its own result first, so a healthy container is
+# a fast no-op that still prints why it is healthy. The last step is the only
+# one that means anything: it launches a browser for real.
+#
+# The things that go wrong, in the order they bite:
+#
+#   1. @playwright/cli missing — including the case where it was installed and
+#      then silently removed again. `npm install --no-save <pkg>` in /workspace,
+#      which has no package.json, prunes packages npm considers extraneous, so
+#      installing @playwright/cli and then installing playwright wipes the
+#      first one and leaves an empty node_modules/@playwright/. That directory
+#      reads as "installed" to a naive check, which is why this script tests
+#      the package *entry point*.
+#
+#   2. Bundled chromium missing or the wrong revision. Browsers live in the
+#      home volume and outlive any single @playwright/cli install, so a stale
+#      chromium-<old> is routinely present while the installed playwright-core
+#      wants a newer one. Must be installed AS claude: run as root it lands in
+#      /root/.cache/ms-playwright where the agent cannot see it.
+#
+#   3. No cli.config.json — the one that breaks an otherwise clean install.
+#      With no config, playwright-cli resolves to channel `chrome` (system
+#      Google Chrome) with the sandbox ON. These containers forbid unprivileged
+#      user namespaces, so Chrome aborts with "Failed to move to new namespace
+#      ... Operation not permitted". On newer base images Chrome is not present
+#      at all and it fails with "Chromium distribution 'chrome' is not found".
+#      Same root cause both ways: the default channel is wrong here.
+#
+#   4. The storage-state file the config points at is missing. Playwright
+#      treats an unreadable storageState as a hard error on every launch, not
+#      as "no saved state", so the file has to exist from the very first run.
+#
+#   5. xvfb or socat missing (older base images only). Headless Playwright
+#      needs neither; the `playwright-cli show` dashboard needs xvfb, and the
+#      browser-view pane needs socat — without it the pane reports
+#      "127.0.0.1 sent an invalid response" while the container side is fine.
+#
+# Usage: triple-c-playwright-heal [--seed-config-only] [--force-config] [--quiet]
+#   --seed-config-only  only ensure the config and its storage-state file
+#                       exist. No npm install, no browser download, no apt, no
+#                       verify launch. Cheap and offline — this is the mode
+#                       entrypoint.sh runs on every container start.
+#   --force-config      overwrite an existing config instead of keeping it
+#   --quiet             print only problems and repairs, not healthy no-ops
+
+set -u
+
+TARGET_USER=claude
+TARGET_HOME=/home/claude
+PW_DIR=/workspace
+CONFIG_DIR="$TARGET_HOME/.playwright"
+CONFIG_FILE="$CONFIG_DIR/cli.config.json"
+STATE_FILE="$CONFIG_DIR/storage-state.json"
+CLI_ENTRY="$PW_DIR/node_modules/@playwright/cli/playwright-cli.js"
+
+FORCE_CONFIG=0
+QUIET=0
+SEED_ONLY=0
+for arg in "$@"; do
+    case "$arg" in
+        --force-config)     FORCE_CONFIG=1 ;;
+        --quiet)            QUIET=1 ;;
+        --seed-config-only) SEED_ONLY=1 ;;
+        *) echo "playwright-heal: unknown option: $arg" >&2; exit 2 ;;
+    esac
+done
+
+changed=0
+failed=0
+
+say()  { [ "$QUIET" = 1 ] || echo "playwright-heal: $*"; }
+warn() { echo "playwright-heal: $*" >&2; }
+did()  { changed=1; echo "playwright-heal: $*"; }
+
+# Run as claude whether we were invoked as root (docker exec / entrypoint) or
+# as claude (terminal session). Nothing user-visible may end up root-owned.
+as_claude() {
+    if [ "$(id -u)" = 0 ]; then
+        su "$TARGET_USER" -s /bin/sh -c "$1"
+    else
+        sh -c "$1"
+    fi
+}
+
+# ── 1. @playwright/cli ───────────────────────────────────────────────────────
+if [ "$SEED_ONLY" = 1 ]; then
+    :
+elif [ -f "$CLI_ENTRY" ]; then
+    say "@playwright/cli present"
+else
+    # An empty leftover @playwright/ can make npm consider the tree settled.
+    if [ -d "$PW_DIR/node_modules/@playwright" ]; then
+        say "clearing partial @playwright install"
+        rm -rf "$PW_DIR/node_modules/@playwright"
+    fi
+    say "installing @playwright/cli..."
+    if as_claude "cd $PW_DIR && npm install --no-save --no-audit --no-fund @playwright/cli" >/tmp/pw-heal-npm.log 2>&1; then
+        did "installed @playwright/cli"
+    else
+        warn "npm install failed; see /tmp/pw-heal-npm.log"
+        failed=1
+    fi
+fi
+
+# ── 2. bundled chromium ──────────────────────────────────────────────────────
+# Ask Playwright where *this* version's chromium belongs rather than globbing
+# chromium-*, which would call a stale revision "present" and then fail at
+# launch with 'Browser "chrome-for-testing" is not installed'. --dry-run prints
+# the install location for the installed version and downloads nothing.
+if [ "$SEED_ONLY" = 1 ]; then
+    :
+else
+    chromium_dir=""
+    if [ -f "$PW_DIR/node_modules/playwright-core/cli.js" ]; then
+        chromium_dir=$(as_claude "cd $PW_DIR && node node_modules/playwright-core/cli.js install --dry-run chromium 2>/dev/null" \
+                       | awk '/Install location:/ { print $3; exit }')
+    fi
+
+    if [ -n "$chromium_dir" ] && [ -d "$chromium_dir" ]; then
+        say "chromium present ($(basename "$chromium_dir"))"
+    elif [ -f "$PW_DIR/node_modules/playwright-core/cli.js" ]; then
+        say "downloading chromium (~300 MB)..."
+        if as_claude "cd $PW_DIR && node node_modules/playwright-core/cli.js install chromium" >/tmp/pw-heal-browser.log 2>&1; then
+            did "installed chromium"
+        else
+            warn "chromium install failed; see /tmp/pw-heal-browser.log"
+            failed=1
+        fi
+    else
+        warn "playwright-core missing, cannot install chromium"
+        failed=1
+    fi
+fi
+
+# ── 3. cli.config.json ───────────────────────────────────────────────────────
+# The *global* config, not a project-level .playwright/, because the project
+# one resolves relative to the current working directory and silently stops
+# applying the moment you cd elsewhere.
+#
+# `chrome-for-testing` is the only recognised chromium alias — "chromium" is
+# not one and falls back to system Chrome. chromiumSandbox:false is what
+# actually appends --no-sandbox.
+write_config() {
+    mkdir -p "$CONFIG_DIR" || return 1
+    cat > "$CONFIG_FILE" <<EOF
+{
+  "browser": {
+    "browserName": "chromium",
+    "launchOptions": {
+      "channel": "chrome-for-testing",
+      "chromiumSandbox": false,
+      "args": ["--no-sandbox", "--disable-dev-shm-usage"]
+    },
+    "contextOptions": {
+      "storageState": "$STATE_FILE"
+    }
+  }
+}
+EOF
+    chown -R "$TARGET_USER:$TARGET_USER" "$CONFIG_DIR" 2>/dev/null || true
+}
+
+# storageState is a *load* path, and Playwright reads it at context creation.
+# A path that does not exist is not treated as "no saved state" — it is a hard
+# error, "Error reading storage state from …", on every single launch. So the
+# file has to exist before the config that names it can be used at all, and it
+# has to be recreated if anything deletes it. An empty state is valid and
+# behaves exactly like no state.
+#
+# The path is read back out of the config rather than assumed, so a
+# hand-edited config pointing somewhere else still gets its file created
+# instead of being silently broken by ours.
+ensure_state_file() {
+    [ -f "$CONFIG_FILE" ] || return 0
+    state_path=$(grep -o '"storageState"[[:space:]]*:[[:space:]]*"[^"]*"' "$CONFIG_FILE" 2>/dev/null \
+                 | sed 's/.*"\([^"]*\)"[[:space:]]*$/\1/')
+    [ -n "$state_path" ] || return 0
+    [ -f "$state_path" ] && return 0
+    mkdir -p "$(dirname "$state_path")" 2>/dev/null
+    printf '{\n  "cookies": [],\n  "origins": []\n}\n' > "$state_path" || return 1
+    chown "$TARGET_USER:$TARGET_USER" "$state_path" 2>/dev/null || true
+    did "created empty $state_path (storageState needs it to exist)"
+}
+
+if [ ! -f "$CONFIG_FILE" ]; then
+    if write_config; then did "wrote $CONFIG_FILE"; else warn "could not write $CONFIG_FILE"; failed=1; fi
+elif [ "$FORCE_CONFIG" = 1 ]; then
+    if write_config; then did "overwrote $CONFIG_FILE (--force-config)"; else warn "could not write $CONFIG_FILE"; failed=1; fi
+elif grep -q '"chromiumSandbox"[[:space:]]*:[[:space:]]*false' "$CONFIG_FILE" 2>/dev/null; then
+    say "config present and disables the sandbox"
+else
+    # Present but hand-edited into a state that will not launch. Do not clobber
+    # deliberate config silently; say what is wrong and how to replace it.
+    warn "config at $CONFIG_FILE does not set chromiumSandbox:false — the browser will likely fail to launch. Re-run with --force-config to replace it."
+fi
+
+# Unconditional: the config may name a storageState this run did not write —
+# one seeded by an older version of this script, or edited by hand — and a
+# missing file there breaks every launch.
+ensure_state_file || { warn "could not create the storage-state file"; failed=1; }
+
+if [ "$SEED_ONLY" = 1 ]; then
+    [ "$failed" = 1 ] && exit 1
+    exit 0
+fi
+
+# ── 4. xvfb (headed dashboard only) ──────────────────────────────────────────
+# Current base images get this from `playwright install-deps` (its `tools`
+# group); older ones predate that layer. Headless never needs it, so a missing
+# xvfb is a note, not a failure.
+if command -v Xvfb >/dev/null 2>&1; then
+    say "xvfb present"
+elif [ "$(id -u)" = 0 ]; then
+    say "installing xvfb (needed only for the headed dashboard)..."
+    if (apt-get update -qq && DEBIAN_FRONTEND=noninteractive apt-get install -y -qq xvfb) >/tmp/pw-heal-xvfb.log 2>&1; then
+        did "installed xvfb"
+    else
+        warn "xvfb install failed (headless still works); see /tmp/pw-heal-xvfb.log"
+    fi
+else
+    say "xvfb missing and not running as root — skipping (headless still works)"
+fi
+
+# ── 4b. socat (the browser-view pane's tunnel) ───────────────────────────────
+# Not Playwright's, but the same class of failure and it presents as a
+# Playwright problem: the pane's host-side proxy reaches the dashboard by
+# running `socat` *inside* the container over a Docker exec. On a container old
+# enough to predate socat in the base image, that exec produces something that
+# is not an HTTP response, and the webview reports "127.0.0.1 sent an invalid
+# response" — with the container side working perfectly. A project keeps the
+# base image it was first built from until it is migrated, so this is the
+# normal case on an older project, not an exotic one.
+if command -v socat >/dev/null 2>&1; then
+    say "socat present"
+elif [ "$(id -u)" = 0 ]; then
+    say "installing socat (needed by the browser-view pane)..."
+    if (apt-get update -qq && DEBIAN_FRONTEND=noninteractive apt-get install -y -qq socat) >/tmp/pw-heal-socat.log 2>&1; then
+        did "installed socat"
+    else
+        warn "socat install failed; the browser-view pane will report an invalid response. See /tmp/pw-heal-socat.log"
+        failed=1
+    fi
+else
+    warn "socat missing and not running as root — the browser-view pane will report an invalid response"
+fi
+
+# ── 5. verify by actually launching ──────────────────────────────────────────
+# Every step above can report success while the browser still refuses to
+# start — that is precisely how this broke. A dedicated session name keeps
+# this clear of whatever the agent already has open.
+if [ -f "$CLI_ENTRY" ]; then
+    verify_out=$(as_claude "cd /tmp && timeout 90 node $CLI_ENTRY -s=heal-verify open 'data:text/html,<h1>ok</h1>' 2>&1")
+    if printf '%s' "$verify_out" | grep -q 'opened with pid'; then
+        say "verified: browser launches"
+        as_claude "cd /tmp && timeout 30 node $CLI_ENTRY -s=heal-verify close" >/dev/null 2>&1
+    else
+        warn "browser still fails to launch:"
+        printf '%s\n' "$verify_out" | grep -m4 -E 'namespace|Check failed|is not installed|is not found|missing dependencies|Error' >&2
+        failed=1
+    fi
+else
+    warn "@playwright/cli not installed — nothing to verify"
+    failed=1
+fi
+
+[ "$failed" = 1 ] && exit 1
+[ "$changed" = 1 ] && say "done — repairs applied" || say "done — nothing to repair"
+exit 0