fix(conversation): topic chips after warmup + English chip copy

- Buffer topic_suggestions until chat UI attaches (uiOwner + callback); replay on attach
- build_topic_chips respects user language for label/text; router passes user_language

Co-authored-by: Cursor <cursoragent@cursor.com>

app-expo/tests/features/conversation/realtime-session-sync-order.test.ts

@@ -250,4 +250,52 @@ describe('RealtimeSession sync TTS / agent ordering', () => {
     expect(staleScreenOnTts).not.toHaveBeenCalled();
     session.dispose();
   });
+
+  it('replays topic_suggestions after attachUiCallbacks with owner (warmup path)', async () => {
+    const onTopic = jest.fn();
+    const owner = Symbol('ui');
+    const session = new RealtimeSession({
+      conversationId: 'conv-x',
+      queryClient: qc,
+    });
+
+    await session.connect();
+    await new Promise((r) => setImmediate(r));
+
+    const ws = MockWebSocket.instances[0]!;
+    ws.simulateMessage({
+      type: 'topic_suggestions',
+      conversation_id: 'conv-x',
+      data: {
+        reason: 'opening',
+        stage: 'childhood',
+        suggestions: [
+          {
+            id: 'place',
+            label: 'where you grew up',
+            text: "I'd like to talk about where you grew up.",
+          },
+        ],
+      },
+      timestamp: new Date().toISOString(),
+    });
+
+    expect(onTopic).not.toHaveBeenCalled();
+
+    session.attachUiCallbacks(
+      {
+        onTopicSuggestions: onTopic,
+        onStreamingText: () => {},
+        onTtsSegment: () => {},
+        onError: () => {},
+        onStateChange: () => {},
+      },
+      owner,
+    );
+
+    expect(onTopic).toHaveBeenCalledTimes(1);
+    expect(onTopic.mock.calls[0]![0].suggestions[0]!.id).toBe('place');
+
+    session.dispose();
+  });
 });