chore: apply ruff auto-fixes and remove dead AST scripts

multi_agent_conductor.py

@@ -1,7 +1,6 @@
 import ai_client
 import json
 import asyncio
-import threading
 import time
 import traceback
 from typing import List, Optional, Tuple
@@ -242,7 +241,7 @@ def run_worker_lifecycle(ticket: Ticket, context: WorkerContext, context_files:
   parser = ASTParser(language="python")
   for i, file_path in enumerate(context_files):
    try:
-    abs_path = Path(file_path)
+    Path(file_path)
     # (This is a bit simplified, but helps)
     with open(file_path, 'r', encoding='utf-8') as f:
      content = f.read()