fix: the download boot hook imports a model-only module, keeping the membership roster off the fetch path (#4433)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LVjrnpQjRgHdvq95rASoiR

tests/test_download_lane_boot.py

@@ -35,7 +35,7 @@ def calls(monkeypatch):
 
     monkeypatch.setattr(celery_signals, "sync_session_factory", lambda: _Session)
     monkeypatch.setattr(
-        "backend.app.tasks.maintenance.interrupt_orphaned_download_events",
+        "backend.app.services.download_recovery.interrupt_orphaned_download_events",
         lambda session, *, booted_at: seen.append("interrupt") or 0,
     )
     monkeypatch.setattr(
@@ -66,6 +66,6 @@ def test_a_failure_does_not_stop_the_worker_starting(monkeypatch, calls):
         raise RuntimeError("db down")
 
     monkeypatch.setattr(
-        "backend.app.tasks.maintenance.interrupt_orphaned_download_events", boom
+        "backend.app.services.download_recovery.interrupt_orphaned_download_events", boom
     )
     celery_signals._on_worker_ready(sender=_consumer("download"))  # must not raise

tests/test_maintenance.py

@@ -726,7 +726,7 @@ def test_download_lane_boot_closes_pre_boot_events_without_blaming_the_source(db
     from sqlalchemy import select
 
     from backend.app.models import DownloadEvent, Source
-    from backend.app.tasks.maintenance import (
+    from backend.app.services.download_recovery import (
         DOWNLOAD_INTERRUPTED_MESSAGE,
         interrupt_orphaned_download_events,
     )