- Query Neo4j for Academic/Registration periods where now() is between start_time and end_time
- Return period_id, event_type, event_label, start_time, end_time
- Handles missing teacher or Neo4j connection gracefully
- Fixed signature mismatch where enrollment_requests router was passing
filters parameter to get_multi() but method didn't accept it
- get_multi() now accepts optional filters dict and passes it to get_all()