feat(menu-lecteur): refonte UI/UX professionnelle du menu FAB

- FAB : pastille verre depoli 40px + icone sliders (standard options)
- Panneau : en-tete (titre + fermer), verre depoli, ombre profonde, coins arrondis
- Animations ouverture/fermeture (fondu + slide + scale), fermeture Echap + clic exterieur
- Items : hover/active/focus, icones teintees, sections + separateurs raffinés
- Playlist : modale rendue HORS du panneau (backdrop-filter piegeait position:fixed)

src/components/shared/components/add-to-playlist/add-to-playlist.component.ts

@@ -15,6 +15,7 @@ import { forkJoin } from 'rxjs';
   <div [class]="menuItem ? 'relative w-full text-left' : 'relative inline-block text-left'" (click)="$event.stopPropagation();">
     <button (click)="toggleOpen($event)"
             [disabled]="!isAuthenticated()"
+            [style.display]="triggerHidden ? 'none' : ''"
             [class]="menuItem ? 'pm-item' : 'flex items-center space-x-2 bg-slate-700 hover:bg-slate-600 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-red-500/60 disabled:opacity-60 disabled:cursor-not-allowed px-4 py-2 rounded-full transition text-slate-200 font-semibold'"
             [attr.aria-expanded]="open()"
             [attr.aria-haspopup]="true"
@@ -121,6 +122,8 @@ export class AddToPlaylistComponent implements OnInit, OnDestroy {
   @Input() thumbnail?: string;
   /** Rendu « élément de menu » (menu FAB du lecteur) : plein largeur, icon + label. */
   @Input() menuItem = false;
+  /** Masque le bouton déclencheur (déclenchement externe via `open()`). */
+  @Input() triggerHidden = false;
 
   open = signal<boolean>(false);
   loading = signal<boolean>(false);
@@ -155,6 +158,15 @@ export class AddToPlaylistComponent implements OnInit, OnDestroy {
     this.selected.set(new Set());
   }
 
+  /** Ouvre la boîte de dialogue (déclenchement externe, ex. menu FAB). */
+  openDialog(): void {
+    if (!this.isAuthenticated()) return;
+    this.open.set(true);
+    if (this.playlists().length === 0 && !this.loading()) {
+      this.reloadPlaylists();
+    }
+  }
+
   reloadPlaylists(): void {
     this.loading.set(true);
     this.error.set(null);

src/components/watch/watch.component.html

@@ -47,7 +47,13 @@
               @if (likeError(); as lerr) {
                 <div class="px-3 py-1.5 text-[11px] text-red-300">{{ lerr }}</div>
               }
-              <app-add-to-playlist [provider]="provider()" [videoId]="v.videoId" [title]="v.title" [thumbnail]="v.thumbnail" [menuItem]="true"></app-add-to-playlist>
+              <button type="button" (click)="openPlaylist()" class="pm-item">
+                <svg xmlns="http://www.w3.org/2000/svg" class="h-4 w-4" viewBox="0 0 24 24" fill="currentColor" aria-hidden="true">
+                  <path d="M4 6a2 2 0 012-2h12a1 1 0 010 2H6v10a1 1 0 11-2 0V6z" />
+                  <path d="M14 11a1 1 0 011-1h5a1 1 0 110 2h-5a1 1 0 01-1-1zM14 15a1 1 0 011-1h5a1 1 0 110 2h-5a1 1 0 01-1-1zM10 11a1 1 0 112 0v1h1a1 1 0 110 2h-1v1a1 1 0 11-2 0v-1H9a1 1 0 110-2h1v-1z" />
+                </svg>
+                <span class="pm-item-label">Ajouter à une playlist</span>
+              </button>
             }
 
             <button type="button" (click)="toggleTranscript(); closeMenu()" class="pm-item" [attr.aria-expanded]="transcriptOpen()">
@@ -104,6 +110,11 @@
           </div>
         </section>
 
+        <!-- Boîte de dialogue playlist : rendue HORS du menu FAB (le panneau a un
+             `backdrop-filter` qui créerait un bloc de positionnement pour la modale
+             `position: fixed`). Déclencheur masqué, ouvert via openPlaylist(). -->
+        <app-add-to-playlist #addToPlaylist [provider]="provider()" [videoId]="v.videoId" [title]="v.title" [thumbnail]="v.thumbnail" [triggerHidden]="true"></app-add-to-playlist>
+
         @if (loading()) {
           <!-- Squelette des métadonnées pendant /details (le player joue déjà) -->
           <div class="mt-4 animate-pulse space-y-3" aria-hidden="true">

src/components/watch/watch.component.ts

@@ -54,6 +54,7 @@ export class WatchComponent implements OnDestroy, AfterViewInit {
   private subs = inject(SubscriptionsService);
   private routeSubscription!: Subscription;
   @ViewChild('embedFrame', { static: false }) embedFrame?: ElementRef<HTMLIFrameElement>;
+  @ViewChild('addToPlaylist', { static: false }) addToPlaylist?: AddToPlaylistComponent;
   private attachTryCount = 0;
 
   // --- Chaîne / abonnement ---
@@ -167,6 +168,12 @@ export class WatchComponent implements OnDestroy, AfterViewInit {
   closeMenu(): void {
     this.menuOpen.set(false);
   }
+
+  /** Ouvre la boîte de dialogue playlist (composant rendu hors du menu FAB). */
+  openPlaylist(): void {
+    this.closeMenu();
+    this.addToPlaylist?.openDialog();
+  }
   // Prefer full description if available; otherwise fallback to shortDescription
   descriptionText = computed(() => {
     const v = this.video();