fix: bound Jam recorder startup

Author: Programcode

.audit/agent-verification-loop.tsv

@@ -16,3 +16,4 @@ ts	phase	decision	why	evidence	result
 2026-08-31T16:42:00Z	webkit	reran the full Safari-engine matrix after rebase	main changed routing and AI code since the first WebKit proof	Playwright 1.60 Noble container with Node 22	56 WebKit cases passed
 2026-08-31T16:56:00Z	CodeRabbit	fixed all four current-head review comments	restricted trusted staging triggers and loopback auth, updated plan state, and sequenced Jam before app startup	PR 21 review on 5f0f67a	all findings implemented or bounded with deterministic proof
 2026-08-31T16:59:00Z	local gates	reran CI-equivalent checks after CodeRabbit fixes	review changes affected workflow security and application bootstrap	npm run verify, Playwright 1.60 Noble container	89 files, 930 tests, coverage, build, 112 Chromium and 56 WebKit cases passed
+2026-08-31T17:06:00Z	CodeRabbit	added a bounded Jam CDN timeout	prevented a stalled recorder request from blocking application startup	src/jam-loader.ts, src/test/jam-loader.test.ts	20 focused tests, lint, typecheck, build, Chromium and WebKit startup passed

src/jam-loader.ts

@@ -2,6 +2,7 @@ const JAM_SCRIPT_URLS = [
   'https://js.jam.dev/recorder.js',
   'https://js.jam.dev/capture.js',
 ] as const;
+const JAM_SCRIPT_TIMEOUT_MS = 3_000;
 
 interface JamLoaderOptions {
   documentRef?: Document;
@@ -14,14 +15,27 @@ function appendJamModule(documentRef: Document, source: string): Promise<void> {
   ).find((script) => script.src === source);
   if (existing) return Promise.resolve();
 
-  return new Promise((resolve) => {
+  return new Promise((resolve, reject) => {
     const script = documentRef.createElement('script');
     script.type = 'module';
     script.async = false;
     script.src = source;
     script.dataset.jamRecorder = 'true';
-    script.addEventListener('load', () => resolve(), { once: true });
-    script.addEventListener('error', () => resolve(), { once: true });
+
+    let settled = false;
+    const finish = (outcome: () => void) => {
+      if (settled) return;
+      settled = true;
+      clearTimeout(timeoutId);
+      outcome();
+    };
+    const timeoutId = setTimeout(() => {
+      script.remove();
+      finish(() => reject(new Error(`Jam module load timed out: ${source}`)));
+    }, JAM_SCRIPT_TIMEOUT_MS);
+
+    script.addEventListener('load', () => finish(resolve), { once: true });
+    script.addEventListener('error', () => finish(resolve), { once: true });
     documentRef.head.append(script);
   });
 }

src/test/jam-loader.test.ts

@@ -1,11 +1,15 @@
-import { describe, expect, it } from 'vitest';
+import { afterEach, describe, expect, it, vi } from 'vitest';
 import { loadJamRecorder } from '@/jam-loader';
 
 function jamScripts() {
   return Array.from(document.head.querySelectorAll<HTMLScriptElement>('script[data-jam-recorder]'));
 }
 
 describe('Jam recorder loader', () => {
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
   it('does not load recorder scripts when MediaRecorder is unavailable', async () => {
     jamScripts().forEach((element) => element.remove());
 
@@ -33,4 +37,16 @@ describe('Jam recorder loader', () => {
     await loadJamRecorder({ documentRef: document, mediaRecorderAvailable: true });
     expect(jamScripts()).toHaveLength(2);
   });
+
+  it('rejects a stalled Jam load so application bootstrap can continue', async () => {
+    jamScripts().forEach((element) => element.remove());
+    vi.useFakeTimers();
+
+    const loading = loadJamRecorder({ documentRef: document, mediaRecorderAvailable: true });
+    const rejection = expect(loading).rejects.toThrow('Jam module load timed out');
+    await vi.advanceTimersByTimeAsync(3_000);
+
+    await rejection;
+    expect(jamScripts()).toHaveLength(0);
+  });
 });