feat(backend): add durable MAX linking and notification queue

Refs #82

app/db/bootstrap.py

@@ -5,6 +5,7 @@ The only module (besides registration code) that touches both schemas — and on
 
 from app.db import audit as _audit  # noqa: F401  (registers audit_log in clinical metadata)
 from app.db import intake as _intake  # noqa: F401
+from app.db import max_notifications as _max_notifications  # noqa: F401
 from app.db import scheduler as _scheduler  # noqa: F401
 from app.db.clinical import ClinicalBase
 from app.db.identity import IdentityBase