Fix companion stop metadata and token permissions

docs/superpowers/plans/2026-06-09-visual-companion-issues.md

@@ -283,11 +283,11 @@ vs both) and where the textarea renders (frame-level vs opt-in per screen).
 In WSL2 especially, people expect the browser to open.
 
 **Change.** Best-effort opener after the `server-started` JSON is parsed:
-WSL → `cmd.exe /c start`, macOS → `open`, Linux → `xdg-open` only when
-`DISPLAY`/`WAYLAND_DISPLAY` is set. Swallow failures, never block startup, keep
-echoing the URL. Document in `visual-companion.md`. (Consider an opt-out for
-headless/remote runs where popping a browser is wrong — ties into D1's config
-mechanism.)
+Windows/WSL → `rundll32.exe url.dll,FileProtocolHandler <url>`, macOS → `open`,
+Linux → `xdg-open` only when `DISPLAY`/`WAYLAND_DISPLAY` is set. Swallow
+failures, never block startup, keep echoing the URL. Document in
+`visual-companion.md`. (Consider an opt-out for headless/remote runs where
+popping a browser is wrong — ties into D1's config mechanism.)
 
 ### D4 — Light/dark contrast helpers (PR #1683)
 

skills/brainstorming/scripts/server.cjs

@@ -117,6 +117,10 @@ function generateToken() {
   return crypto.randomBytes(32).toString('hex');
 }
 
+function chmodOwnerOnly(file) {
+  try { fs.chmodSync(file, 0o600); } catch (e) { /* best effort */ }
+}
+
 function initialToken() {
   if (process.env.BRAINSTORM_TOKEN) {
     return { value: process.env.BRAINSTORM_TOKEN, source: 'env' };
@@ -124,7 +128,10 @@ function initialToken() {
   if (TOKEN_FILE) {
     try {
       const t = fs.readFileSync(TOKEN_FILE, 'utf-8').trim();
-      if (/^[0-9a-f]{32,}$/i.test(t)) return { value: t, source: 'file' };
+      if (/^[0-9a-f]{32,}$/i.test(t)) {
+        chmodOwnerOnly(TOKEN_FILE);
+        return { value: t, source: 'file' };
+      }
     } catch (e) { /* no prior token recorded */ }
   }
   return { value: generateToken(), source: 'generated' };
@@ -599,7 +606,10 @@ function startServer() {
     if (PORT_FILE && !triedFallback) {
       try { fs.writeFileSync(PORT_FILE, String(PORT)); } catch (e) { /* best effort */ }
       if (TOKEN_FILE) {
-        try { fs.writeFileSync(TOKEN_FILE, TOKEN, { mode: 0o600 }); } catch (e) { /* best effort */ }
+        try {
+          fs.writeFileSync(TOKEN_FILE, TOKEN, { mode: 0o600 });
+          chmodOwnerOnly(TOKEN_FILE);
+        } catch (e) { /* best effort */ }
       }
     }
     const info = JSON.stringify({

skills/brainstorming/scripts/stop-server.sh

@@ -17,6 +17,12 @@ STATE_DIR="${SESSION_DIR}/state"
 PID_FILE="${STATE_DIR}/server.pid"
 SERVER_ID_FILE="${STATE_DIR}/server-instance-id"
 
+mark_stopped() {
+  local reason="$1"
+  rm -f "${STATE_DIR}/server-info"
+  printf '{"reason":"%s","timestamp":%s}\n' "$reason" "$(date +%s)" > "${STATE_DIR}/server-stopped"
+}
+
 read_expected_server_id() {
   [[ -f "$SERVER_ID_FILE" ]] || return 1
   local id
@@ -71,6 +77,7 @@ if [[ -f "$PID_FILE" ]]; then
   # point at an unrelated process after a reboot/PID wraparound.
   if ! is_brainstorm_server "$pid"; then
     rm -f "$PID_FILE" "$SERVER_ID_FILE"
+    mark_stopped "stale_pid"
     echo '{"status": "stale_pid"}'
     exit 0
   fi
@@ -100,6 +107,7 @@ if [[ -f "$PID_FILE" ]]; then
   fi
 
   rm -f "$PID_FILE" "$SERVER_ID_FILE" "${STATE_DIR}/server.log"
+  mark_stopped "stop-server.sh"
 
   # Only delete ephemeral /tmp directories
   if [[ "$SESSION_DIR" == /tmp/* ]]; then

tests/brainstorm-server/lifecycle.test.js

@@ -243,6 +243,41 @@ async function runTests() {
     assert.strictEqual(keyB, keyA, 'restart should reuse the same session key');
   });
 
+  await test('hardens existing persisted token file permissions', async () => {
+    const dir = fs.mkdtempSync('/tmp/bs-token-mode-');
+    const portFile = path.join(dir, '.last-port');
+    const tokenFile = path.join(dir, '.last-token');
+    const token = 'efefefefefefefefefefefefefefefef';
+    let srv = null;
+
+    try {
+      fs.writeFileSync(tokenFile, token, { mode: 0o644 });
+      fs.chmodSync(tokenFile, 0o644);
+      srv = spawn('node', [SERVER], {
+        env: {
+          ...process.env,
+          BRAINSTORM_DIR: path.join(dir, 's1'),
+          BRAINSTORM_PORT_FILE: portFile,
+          BRAINSTORM_TOKEN_FILE: tokenFile,
+          BRAINSTORM_LIFECYCLE_CHECK_MS: 100000
+        }
+      });
+      let out = ''; srv.stdout.on('data', d => out += d.toString());
+      for (let i = 0; i < 60 && !out.includes('server-started'); i++) await sleep(50);
+      assert(out.includes('server-started'), 'server should start with persisted token');
+
+      if (process.platform !== 'win32') {
+        const mode = fs.statSync(tokenFile).mode & 0o777;
+        assert.strictEqual(mode, 0o600, `.last-token mode should be 0600, got ${mode.toString(8)}`);
+      } else {
+        assert(fs.existsSync(tokenFile), 'token file should remain present on Windows');
+      }
+    } finally {
+      await killAndWait(srv);
+      fs.rmSync(dir, { recursive: true, force: true });
+    }
+  });
+
   await test('stored key can authenticate WebSocket after same-port restart', async () => {
     const dir = fs.mkdtempSync('/tmp/bs-reconnect-');
     const portFile = path.join(dir, '.last-port');

tests/brainstorm-server/stop-server.test.sh

@@ -84,6 +84,37 @@ else
   esac
 fi
 
+# --- Test 2b: persistent sessions stop with explicit stopped metadata ---
+SESS="$(mktemp -d "$SCRIPT_DIR/.stop-persistent.XXXXXX")"; track_dir "$SESS"; mkdir -p "$SESS/content" "$SESS/state"
+SERVER_ID="$(new_server_id)"
+printf '%s\n' "$SERVER_ID" > "$SESS/state/server-instance-id"
+BRAINSTORM_DIR="$SESS" BRAINSTORM_PORT=0 node "$SERVER" "--brainstorm-server-id=$SERVER_ID" > /dev/null 2>&1 &
+SRV=$!
+track_pid "$SRV"
+disown "$SRV" 2>/dev/null || true
+for _ in $(seq 1 40); do
+  [[ -f "$SESS/state/server-info" ]] && break
+  sleep 0.1
+done
+echo "$SRV" > "$SESS/state/server.pid"
+OUT="$("$STOP" "$SESS")"
+sleep 0.3
+if kill -0 "$SRV" 2>/dev/null; then
+  bad "persistent brainstorm server still running after stop" "$OUT"
+else
+  wait "$SRV" 2>/dev/null || true
+  untrack_pid "$SRV"
+  if [[ -f "$SESS/state/server-info" ]]; then
+    bad "persistent stop clears server-info" "server-info still exists after: $OUT"
+  elif [[ ! -f "$SESS/state/server-stopped" ]]; then
+    bad "persistent stop writes server-stopped" "server-stopped missing after: $OUT"
+  elif grep -q '"reason":"stop-server.sh"' "$SESS/state/server-stopped"; then
+    ok "persistent stop clears alive metadata and writes server-stopped"
+  else
+    bad "persistent stop writes stop reason" "$(cat "$SESS/state/server-stopped" 2>/dev/null || true)"
+  fi
+fi
+
 # --- Test 3: no pid file ---
 SESS="$(mktemp -d)"; track_dir "$SESS"; mkdir -p "$SESS/state"
 OUT="$("$STOP" "$SESS")"