test(orchestrator): add unit tests for native_orchestrator module

conductor/tracks/native_orchestrator_20260306/plan.md

@@ -28,7 +28,9 @@ Focus: Replace subprocess calls with direct function calls
     - WHERE: `src/native_orchestrator.py` (new file)
     - WHAT: Class with tier methods (generate_tickets, execute_ticket, analyze_error, run_tier4_patch)
 
-- [ ] Task 3.2: Integrate with ConductorEngine
+- [x] Task 3.2: Integrate with ConductorEngine - N/A (ConductorEngine already uses in-process ai_client.send())
+    - ConductorEngine runs workers in thread pool, calls ai_client.send() directly
+    - NativeOrchestrator provides clean API for GUI integration
     - WHERE: `src/multi_agent_conductor.py`
     - WHAT: Use NativeOrchestrator instead of subprocess
     - HOW: Import and call methods directly