fix(serve): align integration test mirrors with merged capability + EventBus changes (#4245)

- qwen-serve-routes.test.ts: expand expected features list to 24, adding
  slow_client_warning (#4237) and workspace_mcp/workspace_skills/
  workspace_providers/session_context/session_supported_commands (#4241).
  Matches EXPECTED_STAGE1_FEATURES in server.test.ts:76-101.
- qwen-serve-baseline.test.ts: update SSE backpressure assertion from 3
  to 4 frames (tick, tick, slow_client_warning, client_evicted). PR #4237
  changed EventBus to force-push a slow_client_warning synthetic frame
  when the per-subscriber queue reaches the 75% warn threshold, before
  the client_evicted terminal frame fires on overflow. Mirrors the unit
  test at eventBus.test.ts:103-122.

Both integration mirrors drifted because integration tests only run on
schedule / workflow_dispatch (release.yml:4-9), not PR CI. Fixes the
release run 25992130532 failure in both Docker and No-Sandbox jobs.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

integration-tests/cli/qwen-serve-baseline.test.ts

@@ -477,8 +477,11 @@ async function measureRssAtSessionCount(sessionCount: number): Promise<{
         // construction (matches the existing eventBus.test.ts:103 pattern).
         const iter = bus.subscribe({ maxQueued: 2, signal: ac.signal });
 
-        // Publish 3 events into a 2-deep queue. The 3rd trips eviction →
-        // a synthetic client_evicted terminal frame is appended.
+        // Publish 3 events into a 2-deep queue:
+        //   - event 2 fills the queue to 100% (above the 75% warn threshold),
+        //     so the bus force-pushes a `slow_client_warning` synthetic frame.
+        //   - event 3 trips the eviction path → terminal `client_evicted` frame.
+        // Resulting order: tick(1), tick(2), slow_client_warning, client_evicted.
         bus.publish({ type: 'tick', data: { i: 1 } });
         bus.publish({ type: 'tick', data: { i: 2 } });
         bus.publish({ type: 'tick', data: { i: 3 } });
@@ -489,8 +492,9 @@ async function measureRssAtSessionCount(sessionCount: number): Promise<{
         }
         ac.abort();
 
-        expect(collected).toHaveLength(3);
-        expect(collected[2]!.type).toBe('client_evicted');
+        expect(collected).toHaveLength(4);
+        expect(collected[2]!.type).toBe('slow_client_warning');
+        expect(collected[3]!.type).toBe('client_evicted');
         snapshot.sseBackpressure = {
           ringSize: 4_000,
           maxQueuedDefault: 256,

integration-tests/cli/qwen-serve-routes.test.ts

@@ -198,12 +198,18 @@ describe('qwen serve — capabilities envelope', () => {
       'session_prompt',
       'session_cancel',
       'session_events',
+      'slow_client_warning',
       'typed_event_schema',
       'session_set_model',
       'client_identity',
       'client_heartbeat',
       'session_permission_vote',
       'permission_vote',
+      'workspace_mcp',
+      'workspace_skills',
+      'workspace_providers',
+      'session_context',
+      'session_supported_commands',
       'session_close',
       'session_metadata',
     ]);