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

tests/test_agent_capabilities.py

@@ -1,11 +1,9 @@
-import pytest
 import sys
 import os
 
 # Ensure project root is in path
 sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
-import ai_client
 
 def test_agent_capabilities_listing() -> None:
  pass