feat(gui): implement Phases 2-5 of Comprehensive GUI UX track

- Add cost tracking with new cost_tracker.py module
- Enhance Track Proposal modal with editable titles and goals
- Add Conductor Setup summary and New Track creation form to MMA Dashboard
- Implement Task DAG editing (add/delete tickets) and track-scoped discussion
- Add visual polish: color-coded statuses, tinted progress bars, and node indicators
- Support live worker streaming from AI providers to GUI panels
- Fix numerous integration test regressions and stabilize headless service

tests/mock_gemini_cli.py

@@ -65,7 +65,7 @@ def main() -> None:
   print(json.dumps({
      "type": "message", 
      "role": "assistant",
-     "content": "SUCCESS: Mock Tier 3 worker implemented the change. [MOCK OUTPUT]"
+     "content": "I have processed the tool results and here is the final answer."
     }), flush=True)
   print(json.dumps({
      "type": "result", 
@@ -75,11 +75,17 @@ def main() -> None:
     }), flush=True)
   return
   
- # Default flow: simply return a message instead of making a tool call that blocks the test.
+ # Default flow: emit a tool call to test multi-round looping
  print(json.dumps({
     "type": "message",
     "role": "assistant",
-    "content": "SUCCESS: Mock Tier 3 worker implemented the change. [MOCK OUTPUT]"
+    "content": "I need to check the directory first."
+   }), flush=True)
+ print(json.dumps({
+    "type": "tool_use",
+    "name": "list_directory",
+    "id": "mock-call-1",
+    "args": {"dir_path": "."}
    }), flush=True)
  print(json.dumps({
     "type": "result",