maven: fix test mocks for CalendarEvents interface (verification)

- Add CalendarEvents method to recordingAPI in auth_test.go
- Add CalendarEvents method to fakeCore in handlers_test.go

Co-Authored-By: opencode <opencode@anthropic.com>

internal/store/store.go

@@ -123,4 +123,4 @@ var (
 	ErrConfidence = errors.New("store: confidence must be in (0.0, 1.0]")
 	// ErrVoidsMissing — a correction pointed at a nonexistent fact.
 	ErrVoidsMissing = errors.New("store: voids_id does not reference an existing fact")
-)
+)