style(v2): normalize worker lifecycle imports

backend/src/backup_tool/cli.py

@@ -7,9 +7,9 @@ import asyncio
 from collections.abc import Callable, Sequence
 from pathlib import Path
 
+from alembic import command
 from alembic.config import Config
 
-from alembic import command
 from backup_tool import __version__
 from backup_tool.config import Settings
 

backend/src/backup_tool/worker.py

@@ -6,6 +6,7 @@ The worker owns leases; backup publishing is deliberately supplied by later M6 w
 from __future__ import annotations
 
 import asyncio
+import contextlib
 import signal
 from datetime import UTC, datetime
 from uuid import uuid4
@@ -67,10 +68,8 @@ class Worker:
         await self.startup()
         while not self._stopping.is_set():
             if not await self.run_once():
-                try:
+                with contextlib.suppress(TimeoutError):
                     await asyncio.wait_for(self._stopping.wait(), timeout=0.25)
-                except TimeoutError:
-                    pass
         await self.engine.dispose()
 
     def stop(self) -> None:
@@ -81,10 +80,8 @@ def run_worker(settings: Settings) -> int:
     worker = Worker(settings)
     loop = asyncio.new_event_loop()
     for sig in (signal.SIGINT, signal.SIGTERM):
-        try:
+        with contextlib.suppress(NotImplementedError):
             loop.add_signal_handler(sig, worker.stop)
-        except NotImplementedError:
-            pass
     try:
         loop.run_until_complete(worker.run())
     finally: