Running the test suite without a local `registration.yaml` previously
caused a TypeError because the `reg` export defaulted to null. This
injects a base template using `getTemplateRegistration` before applying
test-specific overrides.
Wrap the scheduled event lookup in a try-catch block to prevent the
bridge from crashing when it encounters expired or invalid links.
When a 404 or Discord error code 10006 is caught, the bot now
generates a fallback "m.notice" event to inform Matrix users that
the event link has expired.