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/loop/feedback.go

@@ -119,4 +119,4 @@ func ParseCooldownFact(f store.Fact) (time.Duration, bool) {
 func MarshalCooldown(d time.Duration) string {
 	b, _ := json.Marshal(int64(d)) // int64 marshal never errors
 	return string(b)
-}
+}