fix(lint): add timezone import, use timedelta directly, remove unused variable

src/fabledassistant/services/briefing_scheduler.py

@@ -13,7 +13,7 @@ functions wrapped with asyncio.run_coroutine_threadsafe().
 
 import asyncio
 import logging
-from datetime import date, datetime, time, timedelta
+from datetime import date, datetime, time, timedelta, timezone
 from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
 
 from apscheduler.schedulers.background import BackgroundScheduler
@@ -170,7 +170,7 @@ async def _auto_pause_stale_projects(user_id: int) -> list[str]:
     from fabledassistant.models import async_session as _session
 
     paused: list[str] = []
-    threshold = datetime.now(timezone.utc) - __import__('datetime').timedelta(days=14)
+    threshold = datetime.now(timezone.utc) - timedelta(days=14)
     try:
         async with _session() as session:
             projects = (await session.execute(
@@ -222,7 +222,7 @@ async def _run_slot_for_user(user_id: int, slot: str) -> None:
 
     if slot == "compilation":
         # Auto-pause stale projects before compiling the briefing
-        auto_paused = await _auto_pause_stale_projects(user_id)
+        await _auto_pause_stale_projects(user_id)
 
         # Refresh external data first
         try: