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/voice/client.go

@@ -40,9 +40,9 @@ type PushHandler interface {
 
 // Client — one connection to the voice.Server.
 type Client struct {
-	addr  string
-	mu    sync.Mutex
-	c     net.Conn
+	addr   string
+	mu     sync.Mutex
+	c      net.Conn
 	nextID atomic.Uint64
 
 	// pushCh fan-out: a reader goroutine (started by RunPushReceiver)
@@ -237,4 +237,4 @@ func marshalParams(v any) (json.RawMessage, error) {
 		return nil, fmt.Errorf("voice: marshal params: %w", err)
 	}
 	return b, nil
-}
+}