feat(mma): complete Phase 6 and finalize Comprehensive GUI UX track

- Implement Live Worker Streaming: wire ai_client.comms_log_callback to Tier 3 streams
- Add Parallel DAG Execution using asyncio.gather for non-dependent tickets
- Implement Automatic Retry with Model Escalation (Flash-Lite -> Flash -> Pro)
- Add Tier Model Configuration UI to MMA Dashboard with project TOML persistence
- Fix FPS reporting in PerformanceMonitor to prevent transient 0.0 values
- Update Ticket model with retry_count and dictionary-like access
- Stabilize Gemini CLI integration tests and handle script approval events in simulations
- Finalize and verify all 6 phases of the implementation plan

tests/test_gui_streaming.py

@@ -102,3 +102,35 @@ def test_handle_ai_response_resets_stream(app_instance: App):
  # (sometimes streaming chunks don't perfectly match final text if there are 
  # tool calls or specific SDK behaviors).
  assert app_instance.mma_streams[stream_id] == "Final complete response."
+
+def test_handle_ai_response_streaming(app_instance: App):
+ """Verifies that 'handle_ai_response' with status='streaming...' appends to mma_streams."""
+ stream_id = "Tier 3 (Worker): T-001"
+ 
+ # 1. First chunk
+ with app_instance._pending_gui_tasks_lock:
+  app_instance._pending_gui_tasks.append({
+    "action": "handle_ai_response",
+    "payload": {
+     "stream_id": stream_id,
+     "text": "Chunk 1. ",
+     "status": "streaming..."
+    }
+   })
+ app_instance._process_pending_gui_tasks()
+ assert app_instance.mma_streams[stream_id] == "Chunk 1. "
+ 
+ # 2. Second chunk
+ with app_instance._pending_gui_tasks_lock:
+  app_instance._pending_gui_tasks.append({
+    "action": "handle_ai_response",
+    "payload": {
+     "stream_id": stream_id,
+     "text": "Chunk 2.",
+     "status": "streaming..."
+    }
+   })
+ app_instance._process_pending_gui_tasks()
+ 
+ # 3. Verify final state
+ assert app_instance.mma_streams[stream_id] == "Chunk 1. Chunk 2."