feat: autoscroll standard, visualizzazione tag/date e OCR spaziale avanzato

- Aggiunto autoscroll standard con controllo velocità (V1-V10) e relativo toggle in settings.
- Implementata la visualizzazione opzionale di tag e data aggiornamento nella lista canti.
- Rinnovata la pagina 'Proponi Canto' con tastiera accordi (fondamentale + variazioni) e OCR spaziale potenziato per l'allineamento automatico degli accordi con il testo.
- Ottimizzata la persistenza della modalità schermo intero.

src/app/pages/propose-canto/propose-canto.page.html

@@ -4,11 +4,6 @@
       <ion-back-button defaultHref="/home" color="secondary"></ion-back-button>
     </ion-buttons>
     <ion-title class="outfit-font">Mio Canto</ion-title>
-    <ion-buttons slot="end">
-      <ion-button (click)="isHighContrast = !isHighContrast" [color]="isHighContrast ? 'warning' : 'medium'">
-        <ion-icon slot="icon-only" name="contrast-outline"></ion-icon>
-      </ion-button>
-    </ion-buttons>
   </ion-toolbar>
 </ion-header>
 
@@ -58,9 +53,28 @@
         </div>
       </div>
 
+      <!-- Main Chords Selector Toolbar -->
       <div class="toolbar-section">
-        <div class="horizontal-toolbar chords-toolbar">
-          <ion-button size="small" *ngFor="let chord of commonChords" (click)="insertChord(chord)">
+        <div class="horizontal-toolbar main-chords-toolbar">
+          <ion-button 
+            *ngFor="let group of groupedChords" 
+            size="small" 
+            [fill]="selectedRootChord === group.root ? 'solid' : 'outline'"
+            [color]="selectedRootChord === group.root ? 'secondary' : 'light'"
+            (click)="selectRoot(group.root)">
+            {{ group.root }}
+          </ion-button>
+        </div>
+      </div>
+
+      <!-- Variations Toolbar (only visible if a root chord is selected) -->
+      <div class="toolbar-section variations-container" *ngIf="selectedRootChord">
+        <div class="horizontal-toolbar variations-toolbar">
+          <span class="variations-label">Variazioni {{ selectedRootChord }}:</span>
+          <ion-button 
+            size="small" 
+            *ngFor="let chord of getVariations()" 
+            (click)="insertChord(chord)">
             {{ chord }}
           </ion-button>
         </div>
@@ -79,9 +93,6 @@
             <ion-button fill="clear" size="small" (click)="takePhoto()">
               <ion-icon name="camera-outline"></ion-icon>
             </ion-button>
-            <ion-button fill="clear" size="small" (click)="uploadDoc()">
-              <ion-icon name="document-text-outline"></ion-icon>
-            </ion-button>
           </div>
         </div>
         <ion-item class="custom-input-item textarea-item">
@@ -90,8 +101,7 @@
             [(ngModel)]="content" 
             placeholder="Scrivi o scansiona..." 
             rows="18" 
-            class="content-textarea"
-            (click)="openQuickMenu($event)">
+            class="content-textarea">
           </ion-textarea>
         </ion-item>
       </div>
@@ -111,34 +121,8 @@
     </div>
   </div>
 
-  <!-- QUICK INSERT POPOVER -->
-  <ion-popover [isOpen]="isChordPopoverOpen" (didDismiss)="isChordPopoverOpen = false" class="quick-popover">
-    <ng-template>
-      <ion-content class="ion-padding">
-        <div class="popover-container">
-          <div class="popover-section">
-            <h6>Struttura e Tag</h6>
-            <div class="popover-grid tags-grid">
-              <ion-button *ngFor="let tag of commonTags" size="small" fill="outline" (click)="insertText(tag.start); isChordPopoverOpen = false">
-                {{ tag.label }}
-              </ion-button>
-            </div>
-          </div>
 
-          <div class="popover-section">
-            <h6>Accordi Comuni</h6>
-            <div class="popover-grid chords-grid">
-              <ion-button *ngFor="let chord of commonChords" size="small" (click)="insertChord(chord); isChordPopoverOpen = false">
-                {{ chord }}
-              </ion-button>
-            </div>
-          </div>
-        </div>
-      </ion-content>
-    </ng-template>
-  </ion-popover>
 
   <!-- Hidden inputs -->
   <input type="file" #cameraInput (change)="onFileSelected($event, true)" accept="image/*" capture="camera" style="display: none;">
-  <input type="file" #docInput (change)="onFileSelected($event, false)" accept=".pdf,.docx,.txt,.odt" style="display: none;">
 </ion-content>