activities.py:
- init_session_factory(url): module-level async_sessionmaker init,
called once from worker.py before workers start
- load_activity_definition(activity_id): queries activity_definitions
by UUID, returns JSON-serialisable dict; raises ApplicationError
(non_retryable=True) if row not found
worker.py:
- reads ACTCORE_DB_URL at startup, fails fast if missing
- calls init_session_factory() before connecting to Temporal
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>