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/config/config_test.go

@@ -187,4 +187,4 @@ func TestDurationRoundTrip(t *testing.T) {
 	if d2 != d {
 		t.Errorf("round-trip = %v, want %v", d2, d)
 	}
-}
+}