fix(mma): Unblock visual simulation - event routing, loop passing, adapter preservation

Three independent root causes fixed:
- gui_2.py: Route mma_spawn_approval/mma_step_approval events in _process_event_queue
- multi_agent_conductor.py: Pass asyncio loop from ConductorEngine.run() through to
  thread-pool workers for thread-safe event queue access; add _queue_put helper
- ai_client.py: Preserve GeminiCliAdapter in reset_session() instead of nulling it

Test: visual_sim_mma_v2::test_mma_complete_lifecycle passes in ~8s

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/temp_project.toml

@@ -12,7 +12,7 @@ auto_scroll_tool_calls = true
 output_dir = "./md_gen"
 
 [files]
-base_dir = "."
+base_dir = "tests/temp_workspace"
 paths = []
 
 [files.tier_assignments]
@@ -37,6 +37,6 @@ web_search = true
 fetch_url = true
 
 [mma]
-epic = "Develop a new feature"
+epic = ""
 active_track_id = ""
 tracks = []