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

conductor/tests/diag_subagent.py

@@ -1,6 +1,5 @@
 import subprocess
 import sys
-import os
 
 def run_diag(role: str, prompt: str) -> str:
  print(f"--- Running Diag for {role} ---")

conductor/tests/test_infrastructure.py

@@ -1,6 +1,4 @@
 import subprocess
-import pytest
-import os
 
 def run_ps_script(role: str, prompt: str) -> subprocess.CompletedProcess:
  """Helper to run the run_subagent.ps1 script."""