refactor(voice): Push-to-Talk-Pfad raus, nur Tap-to-Talk

handlePressIn/Out + onResponderGrant/Release/Terminate weg. Push-to-
Talk lief parallel zu Tap-to-Talk und triggerte je nach Touch-Timing
unkontrollierbar. Stefan kennt das Verhalten ohnehin nicht (sagt
"druecken startet, druecken stoppt") — Push-to-Talk macht UX nur
unklarer ohne Mehrwert.

isLongPress-Ref entfernt (war nur fuer Push-to-Talk-Discrimination).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

android/src/components/VoiceButton.tsx

@@ -44,7 +44,6 @@ const VoiceButton: React.FC<VoiceButtonProps> = ({
   const [meterDb, setMeterDb] = useState(-160);
   const pulseAnim = useRef(new Animated.Value(1)).current;
   const durationTimer = useRef<ReturnType<typeof setInterval> | null>(null);
-  const isLongPress = useRef(false);
 
   // Puls-Animation starten/stoppen
   useEffect(() => {
@@ -117,31 +116,10 @@ const VoiceButton: React.FC<VoiceButtonProps> = ({
     if (disabled || isRecording) return;
     const started = await audioService.startRecording(true); // autoStop = true
     if (started) {
-      isLongPress.current = false;
       setIsRecording(true);
     }
   }, [disabled, isRecording]);
 
-  // Push-to-Talk: Lang druecken
-  const handlePressIn = async () => {
-    if (disabled || isRecording) return;
-    isLongPress.current = true;
-    const started = await audioService.startRecording(false); // kein autoStop
-    if (started) {
-      setIsRecording(true);
-    }
-  };
-
-  const handlePressOut = async () => {
-    if (!isRecording || !isLongPress.current) return;
-    isLongPress.current = false;
-    setIsRecording(false);
-    const result = await audioService.stopRecording();
-    if (result && result.durationMs > 300) {
-      onRecordingComplete(result);
-    }
-  };
-
   // Tap-to-Talk: Einmal tippen startet mit Auto-Stop.
   // Guard gegen Doppel-Tap während asyncer Start/Stop.
   const tapBusy = useRef(false);
@@ -162,7 +140,6 @@ const VoiceButton: React.FC<VoiceButtonProps> = ({
         // Aufnahme mit Auto-Stop starten
         const started = await audioService.startRecording(true);
         if (started) {
-          isLongPress.current = false;
           setIsRecording(true);
         }
       }
@@ -201,10 +178,6 @@ const VoiceButton: React.FC<VoiceButtonProps> = ({
           isRecording && styles.buttonOuterRecording,
           { transform: [{ scale: pulseAnim }] },
         ]}
-        onStartShouldSetResponder={() => true}
-        onResponderGrant={handlePressIn}
-        onResponderRelease={handlePressOut}
-        onResponderTerminate={handlePressOut}
       >
         <TouchableOpacity
           activeOpacity={0.8}