fix(whatsapp): remove shadowing shutil import in cmd_whatsapp (#13364)

The re-pair branch had a redundant 'import shutil' inside cmd_whatsapp,
which made shutil a function-local throughout the whole scope. The
earlier 'shutil.which("npm")' call at the dependency-install step then
crashed with UnboundLocalError before control ever reached the local
import.

shutil is already imported at module level (line 48), so the local
import was dead code anyway. Drop it.

hermes_cli/main.py

@@ -1330,8 +1330,6 @@ def cmd_whatsapp(args):
         except (EOFError, KeyboardInterrupt):
             response = "n"
         if response.lower() in ("y", "yes"):
-            import shutil
-
             shutil.rmtree(session_dir, ignore_errors=True)
             session_dir.mkdir(parents=True, exist_ok=True)
             print("  ✓ Session cleared")