implement six-skill gstack 2 runtime

browse/src/browser-manager.ts

@@ -722,7 +722,7 @@ export class BrowserManager {
     this.consecutiveFailures = 0;
   }
 
-  async close() {
+  async close(timeoutMs = 5000) {
     if (this.browser || (this.connectionMode === 'headed' && this.context)) {
       if (this.connectionMode === 'headed') {
         // Headed/persistent context mode: close the context (which closes the browser)
@@ -730,14 +730,14 @@ export class BrowserManager {
         if (this.browser) this.browser.removeAllListeners('disconnected');
         await Promise.race([
           this.context ? this.context.close() : Promise.resolve(),
-          new Promise(resolve => setTimeout(resolve, 5000)),
+          new Promise(resolve => setTimeout(resolve, timeoutMs)),
         ]).catch(() => {});
       } else {
         // Launched mode: close the browser we spawned
         this.browser.removeAllListeners('disconnected');
         await Promise.race([
           this.browser.close(),
-          new Promise(resolve => setTimeout(resolve, 5000)),
+          new Promise(resolve => setTimeout(resolve, timeoutMs)),
         ]).catch(() => {});
       }
       this.browser = null;
@@ -797,6 +797,11 @@ export class BrowserManager {
     const tabId = id ?? this.activeTabId;
     const page = this.pages.get(tabId);
     if (!page) throw new Error(`Tab ${tabId} not found`);
+    // Capture before page.close(): Playwright may synchronously deliver the
+    // close event, whose map cleanup changes activeTabId to 0. The public
+    // closeTab promise still owns the invariant that closing the active last
+    // tab leaves one usable blank tab.
+    const wasActive = tabId === this.activeTabId;
 
     await page.close();
     this.pages.delete(tabId);
@@ -804,7 +809,7 @@ export class BrowserManager {
     this.tabOwnership.delete(tabId);
 
     // Switch to another tab if we closed the active one
-    if (tabId === this.activeTabId) {
+    if (wasActive) {
       const remaining = [...this.pages.keys()];
       if (remaining.length > 0) {
         this.activeTabId = remaining[remaining.length - 1];
@@ -1568,9 +1573,15 @@ export class BrowserManager {
         console.log('[browse] Handoff: extension not found — headed mode without side panel');
       }
 
-      const userDataDir = path.join(process.env.HOME || '/tmp', '.gstack', 'chromium-profile');
+      const userDataDir = resolveChromiumProfile();
       fs.mkdirSync(userDataDir, { recursive: true });
 
+      // The handoff profile follows the same host-neutral resolution and
+      // stale-lock cleanup contract as launchHeaded(). The current browser is
+      // headless and does not own this persistent profile, so cleanup cannot
+      // disrupt the live rollback path retained below.
+      cleanSingletonLocks(userDataDir);
+
       // T1: same automation-tell-stripping defaults as launchHeaded().
       // The handoff path (headless → headed re-launch) takes the same
       // anti-detection posture.

browse/src/find-security-sidecar.ts

@@ -10,11 +10,15 @@
  *   1. Prefer node on PATH + a bundled JS entry at
  *      browse/dist/security-sidecar.js (built by package.json's
  *      build:security-sidecar script).
- *   2. Dev fallback: node + browse/src/security-sidecar-entry.ts via tsx
- *      (only available in the source checkout, not the compiled install).
- *   3. If Node is missing or no entry resolves, return null. The /pty-inject-scan
+ *   2. If Node is missing or no compiled entry resolves, return null. The
+ *      /pty-inject-scan
  *      endpoint then responds with l4 { available: false } and the extension
  *      degrades to WARN+confirm (D7).
+ *
+ * A plain-Node TypeScript fallback is intentionally not offered. It was not
+ * executable on the supported Node 18 floor and, if partially executed by a
+ * newer Node, could begin downloading local model weights before failing.
+ * GStack 2 does not bundle that model runtime or its weights.
  */
 
 import { existsSync } from "fs";
@@ -46,9 +50,6 @@ function browseRoot(): string {
     if (existsSync(join(candidate, "browse", "dist", "security-sidecar.js"))) {
       return candidate;
     }
-    if (existsSync(join(candidate, "src", "security-sidecar-entry.ts"))) {
-      return candidate;
-    }
     const next = dirname(candidate);
     if (next === candidate) break;
     candidate = next;
@@ -67,12 +68,5 @@ export function findSecuritySidecar(): SidecarLocation | null {
     return { node, entry: compiled, mode: "compiled" };
   }
 
-  // Dev fallback. Compiled installs won't have src/ on disk so this only
-  // resolves when running from the source checkout.
-  const devEntry = join(root, "src", "security-sidecar-entry.ts");
-  if (existsSync(devEntry)) {
-    return { node, entry: devEntry, mode: "dev" };
-  }
-
   return null;
 }

browse/src/meta-commands.ts

@@ -421,14 +421,17 @@ export async function handleMetaCommand(
     }
 
     case 'stop': {
-      await shutdown();
+      // Return the acknowledgement before closing the listener. Shutting down
+      // inline resets the CLI's fetch, which it reasonably interprets as a
+      // crash and then restarts the daemon it was asked to stop.
+      setTimeout(() => { void shutdown(); }, 25).unref?.();
       return 'Server stopped';
     }
 
     case 'restart': {
       // Signal that we want a restart — the CLI will detect exit and restart
       console.log('[browse] Restart requested. Exiting for CLI to restart.');
-      await shutdown();
+      setTimeout(() => { void shutdown(); }, 25).unref?.();
       return 'Restarting...';
     }