feat: condivisione e importazione automatica del codice comunità nelle playlist con priorità tonalità e autoscroll e rifinitura UI

src/app/services/settings.service.ts

@@ -47,6 +47,9 @@ export class SettingsService {
   /** Attiva autoscroll acustico nel dettaglio canto: true = attivo */
   public enableAcousticAutoscroll = signal<boolean>(false);
 
+  /** Preferenza notazione accordi: diesis o bemolle */
+  public chordNotationPreference = signal<'diesis' | 'bemolle'>('diesis');
+
   private wakeLock: any = null;
 
   // PWA installation signals
@@ -103,6 +106,7 @@ export class SettingsService {
       localStorage.setItem('show-update-date', 'true');
       localStorage.setItem('enable-standard-autoscroll', 'true');
       localStorage.setItem('enable-acoustic-autoscroll', 'false');
+      localStorage.setItem('chord-notation-preference', 'diesis');
       
       // ThemeService high contrast default
       localStorage.setItem('high-contrast', 'true');
@@ -187,6 +191,13 @@ export class SettingsService {
       this.enableAcousticAutoscroll.set(false);
     }
 
+    const savedNotation = localStorage.getItem('chord-notation-preference');
+    if (savedNotation !== null) {
+      this.chordNotationPreference.set(savedNotation === 'bemolle' ? 'bemolle' : 'diesis');
+    } else {
+      this.chordNotationPreference.set('diesis');
+    }
+
     // Sync browser fullscreen state with listeners (supporting vendor prefixes)
     const updateFullscreenState = () => {
       const isFs = !!(
@@ -255,6 +266,10 @@ export class SettingsService {
       localStorage.setItem('enable-acoustic-autoscroll', this.enableAcousticAutoscroll().toString());
     });
 
+    effect(() => {
+      localStorage.setItem('chord-notation-preference', this.chordNotationPreference());
+    });
+
     effect(() => {
       const active = this.keepScreenOn();
       localStorage.setItem('keep-screen-on', active.toString());
@@ -381,6 +396,10 @@ export class SettingsService {
     localStorage.setItem('enable-acoustic-autoscroll', newValue.toString());
   }
 
+  setChordNotationPreference(val: 'diesis' | 'bemolle') {
+    this.chordNotationPreference.set(val);
+  }
+
   async installPwa() {
     const promptEvent = this.deferredPrompt();
     if (!promptEvent) {