fix: sidebar agent uses real tab URL instead of stale Playwright URL (v0.12.6.0) (#544)

* fix: sidebar agent uses extension's activeTabUrl instead of stale Playwright URL

When the user navigates manually in headed Chrome, Playwright's page.url()
stays on the old page. The sidebar agent was using this stale URL in its
system prompt, causing it to navigate to the wrong page (e.g., Hacker News
instead of the user's current page).

The Chrome extension now captures the active tab URL via chrome.tabs.query()
and sends it as activeTabUrl in the /sidebar-command POST body. The server
prefers this over Playwright's URL. The URL is sanitized (http/https only,
control chars stripped, 2048 char limit) to prevent prompt injection.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: connect-chrome pre-flight cleanup + improved onboarding docs

Adds Step 0 pre-flight cleanup that kills stale browse servers and cleans
Chromium profile locks before connecting. Improves the onboarding flow with
clearer instructions for finding the extension, opening the Side Panel, and
troubleshooting connection issues. Fixes Mode check from cdp to headed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* test: sidebar agent test suite (layers 1-2)

Layer 1 (unit): 18 tests for URL sanitization in sidebar-utils.ts — http/https
pass, chrome:// rejected, javascript: rejected, control chars stripped, truncation.

Layer 2 (integration): 13 tests for server HTTP endpoints — auth, sidebar-command
queue writes, activeTabUrl override/fallback, event relay to chat buffer, message
queuing, queue overflow (429), chat clear, agent kill.

Source changes for testability:
- Extract sanitizeExtensionUrl() to browse/src/sidebar-utils.ts
- Add BROWSE_HEADLESS_SKIP env var to skip browser launch in HTTP-only tests
- Add SIDEBAR_QUEUE_PATH env var to both server.ts and sidebar-agent.ts
- Add SIDEBAR_AGENT_TIMEOUT env var to sidebar-agent.ts
- Sync package.json version to match VERSION (0.12.2.0)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* test: sidebar agent round-trip tests with mock claude (layer 3)

Starts server + sidebar-agent together with a mock claude binary (shell script
outputting canned stream-json). Verifies the full queue-based message flow:

- Full round-trip: POST /sidebar-command → queue → agent → mock claude → events → chat
- Claude crash recovery: mock exits 1, agent_error appears, status returns to idle
- Sequential queue drain: two rapid messages both process in order

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* test: sidebar agent E2E tests with real Claude (layer 4)

Two E2E tests that exercise the full sidebar agent flow with real Claude:

- sidebar-navigate: POST /sidebar-command asking Claude to describe a fixture
  page, verify it responds with page content through the chat buffer
- sidebar-url-accuracy: POST with activeTabUrl differing from Playwright URL,
  verify the queue prompt uses the extension URL (the core bug fix)

Both registered as periodic tier (~$0.80 total, non-deterministic).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: sidebar E2E tests — sequential execution + eval collector fix

Both tests now pass:
- sidebar-url-accuracy: deterministic queue file check (no Claude needed)
- sidebar-navigate: real Claude responds through sidebar agent queue

Fixed: testIfSelected (sequential, not concurrent) to avoid queue file
conflicts. Added cost_usd field for eval collector compatibility.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: kill stale sidebar-agent processes before starting new one

Each /connect-chrome starts a new sidebar-agent subprocess with unref()
but never kills the previous one. Old agents accumulate as zombies with
stale auth tokens. When they pick up queue entries, their event relay
fails (401), so the server never receives agent_done and marks the agent
as "hung". The user sees the sidebar freeze.

Fix: pkill any existing sidebar-agent.ts processes before spawning.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: bump version and changelog (v0.12.6.0)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: add P1 TODO for sidebar Write tool + error visibility

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

browse/src/server.ts

@@ -18,6 +18,7 @@ import { handleReadCommand } from './read-commands';
 import { handleWriteCommand } from './write-commands';
 import { handleMetaCommand } from './meta-commands';
 import { handleCookiePickerRoute } from './cookie-picker-routes';
+import { sanitizeExtensionUrl } from './sidebar-utils';
 import { COMMAND_DESCRIPTIONS } from './commands';
 import { handleSnapshot, SNAPSHOT_FLAGS } from './snapshot';
 import { resolveConfig, ensureStateDir, readVersionHash } from './config';
@@ -123,7 +124,7 @@ let sidebarSession: SidebarSession | null = null;
 let agentProcess: ChildProcess | null = null;
 let agentStatus: 'idle' | 'processing' | 'hung' = 'idle';
 let agentStartTime: number | null = null;
-let messageQueue: Array<{message: string, ts: string}> = [];
+let messageQueue: Array<{message: string, ts: string, extensionUrl?: string | null}> = [];
 let currentMessage: string | null = null;
 let chatBuffer: ChatEntry[] = [];
 let chatNextId = 0;
@@ -371,18 +372,27 @@ function processAgentEvent(event: any): void {
   }
 }
 
-function spawnClaude(userMessage: string): void {
+function spawnClaude(userMessage: string, extensionUrl?: string | null): void {
   agentStatus = 'processing';
   agentStartTime = Date.now();
   currentMessage = userMessage;
 
-  const pageUrl = browserManager.getCurrentUrl() || 'about:blank';
+  // Prefer the URL from the Chrome extension (what the user actually sees)
+  // over Playwright's page.url() which can be stale in headed mode.
+  const sanitizedExtUrl = sanitizeExtensionUrl(extensionUrl);
+  const playwrightUrl = browserManager.getCurrentUrl() || 'about:blank';
+  const pageUrl = sanitizedExtUrl || playwrightUrl;
   const B = BROWSE_BIN;
   const systemPrompt = [
     'You are a browser assistant running in a Chrome sidebar.',
-    `Current page: ${pageUrl}`,
+    `The user is currently viewing: ${pageUrl}`,
     `Browse binary: ${B}`,
     '',
+    'IMPORTANT: You are controlling a SHARED browser. The user may have navigated',
+    'manually. Always run `' + B + ' url` first to check the actual current URL.',
+    'If it differs from above, the user navigated — work with the ACTUAL page.',
+    'Do NOT navigate away from the user\'s current page unless they ask you to.',
+    '',
     'Commands (run via bash):',
     `  ${B} goto <url>    ${B} click <@ref>    ${B} fill <@ref> <text>`,
     `  ${B} snapshot -i   ${B} text            ${B} screenshot`,
@@ -404,8 +414,8 @@ function spawnClaude(userMessage: string): void {
   // fails with ENOENT on everything, including /bin/bash). Instead,
   // write the command to a queue file that the sidebar-agent process
   // (running as non-compiled bun) picks up and spawns claude.
-  const gstackDir = path.join(process.env.HOME || '/tmp', '.gstack');
-  const agentQueue = path.join(gstackDir, 'sidebar-agent-queue.jsonl');
+  const agentQueue = process.env.SIDEBAR_QUEUE_PATH || path.join(process.env.HOME || '/tmp', '.gstack', 'sidebar-agent-queue.jsonl');
+  const gstackDir = path.dirname(agentQueue);
   const entry = JSON.stringify({
     ts: new Date().toISOString(),
     message: userMessage,
@@ -414,6 +424,7 @@ function spawnClaude(userMessage: string): void {
     stateFile: config.stateFile,
     cwd: (sidebarSession as any)?.worktreePath || process.cwd(),
     sessionId: sidebarSession?.claudeSessionId || null,
+    pageUrl: pageUrl,
   });
   try {
     fs.mkdirSync(gstackDir, { recursive: true });
@@ -781,12 +792,16 @@ async function start() {
   const port = await findPort();
 
   // Launch browser (headless or headed with extension)
-  const headed = process.env.BROWSE_HEADED === '1';
-  if (headed) {
-    await browserManager.launchHeaded();
-    console.log(`[browse] Launched headed Chromium with extension`);
-  } else {
-    await browserManager.launch();
+  // BROWSE_HEADLESS_SKIP=1 skips browser launch entirely (for HTTP-only testing)
+  const skipBrowser = process.env.BROWSE_HEADLESS_SKIP === '1';
+  if (!skipBrowser) {
+    const headed = process.env.BROWSE_HEADED === '1';
+    if (headed) {
+      await browserManager.launchHeaded();
+      console.log(`[browse] Launched headed Chromium with extension`);
+    } else {
+      await browserManager.launch();
+    }
   }
 
   const startTime = Date.now();
@@ -935,17 +950,21 @@ async function start() {
         if (!msg) {
           return new Response(JSON.stringify({ error: 'Empty message' }), { status: 400, headers: { 'Content-Type': 'application/json' } });
         }
+        // The Chrome extension sends the active tab's URL — prefer it over
+        // Playwright's page.url() which can be stale in headed mode when
+        // the user navigates manually.
+        const extensionUrl = body.activeTabUrl || null;
         const ts = new Date().toISOString();
         addChatEntry({ ts, role: 'user', message: msg });
         if (sidebarSession) { sidebarSession.lastActiveAt = ts; saveSession(); }
 
         if (agentStatus === 'idle') {
-          spawnClaude(msg);
+          spawnClaude(msg, extensionUrl);
           return new Response(JSON.stringify({ ok: true, processing: true }), {
             status: 200, headers: { 'Content-Type': 'application/json' },
           });
         } else if (messageQueue.length < MAX_QUEUE) {
-          messageQueue.push({ message: msg, ts });
+          messageQueue.push({ message: msg, ts, extensionUrl });
           return new Response(JSON.stringify({ ok: true, queued: true, position: messageQueue.length }), {
             status: 200, headers: { 'Content-Type': 'application/json' },
           });
@@ -979,7 +998,7 @@ async function start() {
         // Process next in queue
         if (messageQueue.length > 0) {
           const next = messageQueue.shift()!;
-          spawnClaude(next.message);
+          spawnClaude(next.message, next.extensionUrl);
         }
         return new Response(JSON.stringify({ ok: true }), { status: 200, headers: { 'Content-Type': 'application/json' } });
       }
@@ -1065,7 +1084,7 @@ async function start() {
           // Process next queued message
           if (messageQueue.length > 0) {
             const next = messageQueue.shift()!;
-            spawnClaude(next.message);
+            spawnClaude(next.message, next.extensionUrl);
           } else {
             agentStatus = 'idle';
           }