feat: Enhance Step 9 diagnostics and error handling

- Refactor getStatusBadgeEntries to use createStep9Entry for better encapsulation.
- Introduce error visual signals detection in createStep9Entry.
- Add functions to identify OAuth callback timeout failures and step 9 failure texts.
- Update buildStep9StatusDiagnostics to include error visual summaries and handle conflicts between success and failure states.
- Implement new tests for step 9 diagnostics, ensuring correct behavior with success badges and error banners.
- Remove outdated tests related to step 5 onboarding and redirect race conditions.
- Add new tests for auto-run behavior in step 6 restart scenarios.

tests/background-tab-runtime-module.test.js

@@ -15,3 +15,45 @@ test('tab runtime module exposes a factory', () => {
 
   assert.equal(typeof api?.createTabRuntime, 'function');
 });
+
+test('tab runtime waitForTabComplete waits until tab status becomes complete', async () => {
+  const source = fs.readFileSync('background/tab-runtime.js', 'utf8');
+  const globalScope = {};
+  const api = new Function('self', `${source}; return self.MultiPageBackgroundTabRuntime;`)(globalScope);
+
+  let getCalls = 0;
+  const runtime = api.createTabRuntime({
+    LOG_PREFIX: '[test]',
+    addLog: async () => {},
+    buildLocalhostCleanupPrefix: () => '',
+    chrome: {
+      tabs: {
+        get: async () => {
+          getCalls += 1;
+          return {
+            id: 9,
+            url: 'https://example.com',
+            status: getCalls >= 3 ? 'complete' : 'loading',
+          };
+        },
+        query: async () => [],
+      },
+    },
+    getSourceLabel: (source) => source || 'unknown',
+    getState: async () => ({ tabRegistry: {}, sourceLastUrls: {} }),
+    matchesSourceUrlFamily: () => false,
+    normalizeLocalCpaStep9Mode: () => 'submit',
+    parseUrlSafely: () => null,
+    registerTab: async () => {},
+    setState: async () => {},
+    shouldBypassStep9ForLocalCpa: () => false,
+  });
+
+  const result = await runtime.waitForTabComplete(9, {
+    timeoutMs: 2000,
+    retryDelayMs: 1,
+  });
+
+  assert.equal(result?.status, 'complete');
+  assert.equal(getCalls, 3);
+});