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/test_sim_base.py

@@ -27,4 +27,5 @@ def test_base_simulation_setup() -> None:
   mock_client.wait_for_server.assert_called()
   mock_client.click.assert_any_call("btn_reset")
   mock_sim.setup_new_project.assert_called()
-  assert sim.project_path.endswith("tests/artifacts/temp_testsim.toml")
+  from pathlib import Path
+  assert Path(sim.project_path).as_posix().endswith("tests/artifacts/temp_testsim.toml")