fix: resolve remaining 4 CI test failures (#9543)

- test_auth_commands: suppress _seed_from_singletons auto-seeding that
  adds extra credentials from CI env (same pattern as nearby tests)
- test_interrupt: clear stale _interrupted_threads set to prevent
  thread ident reuse from prior tests in same xdist worker
- test_code_execution: add watch_patterns to _BLOCKED_TERMINAL_PARAMS
  to match production _TERMINAL_BLOCKED_PARAMS

tests/tools/test_code_execution.py

@@ -380,7 +380,7 @@ class TestStubSchemaDrift(unittest.TestCase):
     # Parameters that are internal (injected by the handler, not user-facing)
     _INTERNAL_PARAMS = {"task_id", "user_task"}
     # Parameters intentionally blocked in the sandbox
-    _BLOCKED_TERMINAL_PARAMS = {"background", "pty", "notify_on_complete"}
+    _BLOCKED_TERMINAL_PARAMS = {"background", "pty", "notify_on_complete", "watch_patterns"}
 
     def test_stubs_cover_all_schema_params(self):
         """Every user-facing parameter in the real schema must appear in the