fc3h: celery_app — register backup tasks (include + maintenance route + Beat hourly tick + daily prune)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/app/celery_app.py

@@ -31,6 +31,7 @@ def make_celery() -> Celery:
             "backend.app.tasks.migration",
             "backend.app.tasks.ml",
             "backend.app.tasks.download",
+            "backend.app.tasks.backup",
         ],
     )
     app.conf.update(
@@ -43,6 +44,7 @@ def make_celery() -> Celery:
             "backend.app.tasks.scan.*": {"queue": "scan"},
             "backend.app.tasks.maintenance.*": {"queue": "maintenance"},
             "backend.app.tasks.migration.*": {"queue": "maintenance"},
+            "backend.app.tasks.backup.*": {"queue": "maintenance"},
         },
         # Heavy ML tasks need fair dispatch — see ImageRepo's precedent.
         task_acks_late=True,
@@ -89,6 +91,14 @@ def make_celery() -> Celery:
                 "task": "backend.app.tasks.maintenance.prune_task_runs",
                 "schedule": 86400.0,  # daily
             },
+            "fc3h-backup-db-nightly": {
+                "task": "backend.app.tasks.backup.backup_db_nightly",
+                "schedule": 3600.0,  # hourly tick; task self-gates on configured UTC hour
+            },
+            "fc3h-prune-backups": {
+                "task": "backend.app.tasks.backup.prune_backups",
+                "schedule": 86400.0,  # daily
+            },
         },
         timezone="UTC",
     )