fix(extension): delete the dead chat-queue client surface

The sidebar-command handler in background.js POSTed to a server endpoint that
no longer exists (deleted with the chat queue) — ~35 lines of fully-wired dead
code including error handling for the permanent 404, plus its allowlist entry.
No sender in the extension ever emitted the message type.

chatEnabled leaves the /health contract (server hardcoded false, background.js
re-derived it, nothing consumed it — the chat input element it guarded is gone
from sidepanel.html). BROWSE_SIDEBAR_CHAT env flag had zero readers.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

browse/src/cli.ts

@@ -1085,7 +1085,6 @@ Refs:           After 'snapshot', use @e1, @e2... as selectors:
       const serverEnv: Record<string, string> = {
         BROWSE_HEADED: '1',
         BROWSE_PORT: '34567',
-        BROWSE_SIDEBAR_CHAT: '1',
         // Disable parent-process watchdog: the user controls the headed browser
         // window lifecycle. The CLI exits immediately after connect, so watching
         // it would kill the server ~15s later. Cleanup happens via browser

browse/src/server.ts

@@ -1832,10 +1832,6 @@ export function buildFetchHandler(cfg: ServerConfig): ServerHandle {
           mode: browserManager.getConnectionMode(),
           uptime: Math.floor((Date.now() - startTime) / 1000),
           tabs: browserManager.getTabCount(),
-          // The chat queue is gone — Terminal pane is the sole sidebar
-          // surface. Keep `chatEnabled: false` so any older extension
-          // build still treats the chat input as disabled.
-          chatEnabled: false,
           // Security module status — drives the shield icon in the sidepanel.
           // Returns {status: 'protected'|'degraded'|'inactive', layers: {...}}.
           // The chat-path classifier no longer feeds this since

browse/test/sidebar-tabs.test.ts

@@ -205,8 +205,9 @@ describe('server.ts: chat / sidebar-agent endpoints are gone', () => {
     expect(slice).not.toContain('agentStatus');
     expect(slice).not.toContain('messageQueue');
     expect(slice).not.toContain('agentStartTime');
-    // chatEnabled is hardcoded false now (older clients still see the field).
-    expect(slice).toMatch(/chatEnabled:\s*false/);
+    // chatEnabled is gone entirely — the chat pane no longer exists in any
+    // extension build, so /health stopped advertising a chat mode.
+    expect(slice).not.toContain('chatEnabled');
     // terminalPort survives.
     expect(slice).toContain('terminalPort');
   });

extension/background.js

@@ -81,8 +81,7 @@ async function checkHealth() {
       // already flips to disconnected on a 403.
       const gotToken = await loadAuthToken();
       if (!gotToken && !authToken) return;
-      // Forward chatEnabled so sidepanel can show/hide chat tab
-      setConnected({ ...data, chatEnabled: !!data.chatEnabled });
+      setConnected(data);
     } else {
       setDisconnected();
     }
@@ -297,7 +296,7 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
 
   const ALLOWED_TYPES = new Set([
     'getPort', 'setPort', 'getServerUrl', 'getToken', 'fetchRefs',
-    'openSidePanel', 'sidebarOpened', 'command', 'sidebar-command',
+    'openSidePanel', 'sidebarOpened', 'command',
     'getTabState',
     // Inspector message types
     'startInspector', 'stopInspector', 'elementPicked', 'pickerCancelled',
@@ -447,41 +446,6 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
     return true;
   }
 
-  // Sidebar → Claude Code (file-based message queue)
-  if (msg.type === 'sidebar-command') {
-    const base = getBaseUrl();
-    if (!base || !authToken) {
-      sendResponse({ error: 'Not connected' });
-      return true;
-    }
-    // Capture the active tab's URL so the sidebar agent knows what page
-    // the user is actually looking at (Playwright's page.url() can be stale
-    // if the user navigated manually in headed mode).
-    chrome.tabs.query({ active: true, currentWindow: true }, (tabs) => {
-      const activeTabUrl = tabs?.[0]?.url || null;
-      fetch(`${base}/sidebar-command`, {
-        method: 'POST',
-        headers: {
-          'Content-Type': 'application/json',
-          'Authorization': `Bearer ${authToken}`,
-        },
-        body: JSON.stringify({ message: msg.message, activeTabUrl }),
-      })
-        .then(r => {
-          if (!r.ok) {
-            console.error(`[gstack bg] sidebar-command failed: ${r.status} ${r.statusText}`);
-            return r.json().catch(() => ({ error: `Server returned ${r.status}` }));
-          }
-          return r.json();
-        })
-        .then(data => sendResponse(data))
-        .catch(err => {
-          console.error('[gstack bg] sidebar-command error:', err.message);
-          sendResponse({ error: err.message });
-        });
-    });
-    return true;
-  }
 });
 
 // ─── Side Panel ─────────────────────────────────────────────────