refactor: require scheduler task ownership

tests/test_scheduler_lifecycle.py

@@ -2,6 +2,7 @@
 
 import asyncio
 import gc
+import inspect
 import threading
 import warnings
 
@@ -69,6 +70,14 @@ def _scheduler(job_id: str, func) -> Scheduler:
     return scheduler
 
 
+def test_internal_loop_submission_requires_job_owner() -> None:
+    """Scheduler 内部协程桥接不得再提供省略 job owner 的游离提交分支。"""
+    parameter = inspect.signature(Scheduler._submit_to_loop).parameters["job_id"]
+
+    assert parameter.default is inspect.Parameter.empty
+    assert parameter.annotation is str
+
+
 @pytest.mark.anyio
 async def test_stop_async_cancels_and_awaits_scheduler_owned_job(monkeypatch) -> None:
     """关闭后已投递协程必须取消并完成收尾，不得遗留 owner 句柄。"""