Fix selected Preset

src/App.vue

@@ -18,7 +18,7 @@ let nextNoteTime = 0;
 let timerID = null;
 
 const presets = ref(loadPresets());
-let selectedPreset = null;
+let selectedPreset = ref(null);
 
 // Wie weit im Voraus Audio geplant wird
 const scheduleAheadTime = 0.1; // 100 ms
@@ -36,7 +36,7 @@ function clampBpm() {
 function changeBpm(delta) {
   bpm.value = (Number.isFinite(bpm.value) ? bpm.value : 120) + delta;
   clampBpm();
-  selectedPreset = null;
+  selectedPreset = ref(null);
 }
 
 async function loadClickSound() {
@@ -133,15 +133,15 @@ function addPreset() {
 }
 
 function deletePreset() {
-  presets.value = presets.value.filter(f => f.id != selectedPreset.id);
+  presets.value = presets.value.filter(f => f.id != selectedPreset.value.id);
 
   localStorage.setItem(STORAGE_KEY, JSON.stringify(presets.value));
   stop();
-  selectedPreset = null;
+  selectedPreset = ref(null);
 }
 
 function startPreset(preset) {
-  selectedPreset = preset;
+  selectedPreset.value = preset;
   bpm.value = preset.tempo;
 
   if (!isRunning.value) {