fix(matrix-bridge): remove shadowed 'import os' inside lifespan causing UnboundLocalError

Made-with: Cursor

services/matrix-bridge-dagi/app/main.py

@@ -374,7 +374,6 @@ async def lifespan(app_: Any):
             # M2.3: Persistent event deduplication
             _prune_task: Optional[asyncio.Task] = None
             if _cfg.persistent_dedupe:
-                import os
                 db_path = os.path.join(_cfg.bridge_data_dir, "matrix_bridge.db")
                 _event_store = EventStore(
                     db_path=db_path,
@@ -430,7 +429,6 @@ async def lifespan(app_: Any):
             _policy_store: Optional[Any] = None
             try:
                 from .policy_store import PolicyStore as _PolicyStore
-                import os
                 _ps_path = os.path.join(_cfg.bridge_data_dir, "policy_overrides.db")
                 _policy_store = _PolicyStore(db_path=_ps_path)
                 _policy_store.open()