feat(themes): interrupteur global bande des themes + masquee sur watch

- ThemesService: signal barVisible persiste (localStorage), toggle global
- header: bouton oeil afficher/masquer la bande (aria-pressed, FR/EN)
- app: affichage = page autorisee ET interrupteur; allowlist stricte
  (accueil + /t/... uniquement, chemin normalise) -> jamais sur /watch
- i18n: cles themes.showBar/hideBar FR/EN

src/app.component.ts

@@ -6,6 +6,7 @@ import { SidebarComponent } from './components/sidebar/sidebar.component';
 import { ThemesNavComponent } from './components/themes/themes-nav.component';
 import { I18nService } from './services/i18n.service';
 import { AuthService } from './services/auth.service';
+import { ThemesService } from './services/themes.service';
 
 @Component({
   selector: 'app-root',
@@ -18,6 +19,7 @@ export class AppComponent {
   private i18n = inject(I18nService);
   private auth = inject(AuthService);
   private router = inject(Router);
+  private themesSvc = inject(ThemesService);
   sidebarOpen = signal(false);
   sidebarCollapsed = signal(false);
   private _showThemesBar = signal(false);
@@ -59,9 +61,12 @@ export class AppComponent {
 
   private updateShowThemesBar() {
     try {
-      const url = this.router.url || '/';
-      const isHome = url === '/' || url.startsWith('/?');
-      const isTheme = url.startsWith('/t/') || /^\/p\/[^/]+\/t\//.test(url);
+      // Liste blanche stricte : accueil + pages de thèmes uniquement.
+      // /watch, /search, /shorts, /library, /channel... : jamais de bande.
+      const raw = this.router.url || '/';
+      const pathOnly = raw.split('?')[0].split('#')[0] || '/';
+      const isHome = pathOnly === '/' || pathOnly === '';
+      const isTheme = pathOnly.startsWith('/t/') || /^\/p\/[^/]+\/t\//.test(pathOnly);
       this._showThemesBar.set(isHome || isTheme);
     } catch {
       this._showThemesBar.set(false);
@@ -69,5 +74,6 @@ export class AppComponent {
   }
 
   // Template helpers
-  showThemesBar() { return this._showThemesBar(); }
+  // Visible = page autorisée ET interrupteur global du header (persisté).
+  showThemesBar() { return this._showThemesBar() && this.themesSvc.barVisible(); }
 }

src/components/header/header.component.html

@@ -21,6 +21,17 @@
 
     <!-- Right: user -->
     <div class="justify-self-end flex items-center gap-3 pr-3 md:pr-4">
+      <!-- Toggle global de la bande des thèmes -->
+      <button (click)="toggleThemesBar()"
+              [attr.aria-pressed]="themesBarVisible()"
+              [attr.title]="themesBarVisible() ? ('themes.hideBar' | t : 'Masquer la bande des thèmes') : ('themes.showBar' | t : 'Afficher la bande des thèmes')"
+              aria-label="Afficher ou masquer la bande des thèmes"
+              class="p-2 rounded-full text-slate-200 hover:bg-slate-700 focus:outline-none focus-visible:ring-2 focus-visible:ring-red-400"
+              [class.opacity-40]="!themesBarVisible()">
+        <svg xmlns="http://www.w3.org/2000/svg" class="h-5 w-5" viewBox="0 0 24 24" fill="currentColor" aria-hidden="true">
+          <path d="M12 4.5C7 4.5 2.73 7.61 1 12c1.73 4.39 6 7.5 11 7.5s9.27-3.11 11-7.5c-1.73-4.39-6-7.5-11-7.5zM12 17a5 5 0 1 1 0-10 5 5 0 0 1 0 10zm0-8a3 3 0 1 0 0 6 3 3 0 0 0 0-6z"/>
+        </svg>
+      </button>
       <!-- Provider context indicator placed between search and user area -->
       <div *ngIf="providerContextLabel()" class="flex items-center gap-1 text-xs">
         <span class="inline-flex items-center px-2 py-0.5 rounded border shadow-sm gap-1"

src/components/header/header.component.ts

@@ -178,6 +178,12 @@ export class HeaderComponent {
     return p?.label || ctx;
   });
 
+  // Bande des thèmes : interrupteur global (persisté dans ThemesService)
+  themesBarVisible = this.themes.barVisible;
+  toggleThemesBar(): void {
+    this.themes.toggleBarVisible();
+  }
+
   // Theme management (global/local)
   themeOptions = ['system', 'light', 'dark', 'black', 'blue'];
   currentTheme = signal<string>((() => {

src/services/i18n.service.ts

@@ -74,6 +74,8 @@ const EN: Record<string, string> = {
   'themes.title': 'Themes',
   'themes.show': 'Show',
   'themes.hide': 'Hide',
+  'themes.showBar': 'Show the themes bar',
+  'themes.hideBar': 'Hide the themes bar',
   // Common
   'common.error': 'An error occurred.',
   'empty.noItems': 'No items.',
@@ -210,6 +212,8 @@ const FR: Record<string, string> = {
   'themes.title': 'Thèmes',
   'themes.show': 'Afficher',
   'themes.hide': 'Masquer',
+  'themes.showBar': 'Afficher la bande des thèmes',
+  'themes.hideBar': 'Masquer la bande des thèmes',
   // Common
   'common.error': 'Une erreur est survenue.',
   'empty.noItems': 'Aucun élément.',

src/services/themes.service.ts

@@ -16,6 +16,25 @@ export class ThemesService {
   // Controls whether the themes nav should show all themes or only a subset (e.g., 8)
   readonly showAll = signal<boolean>(false);
 
+  /**
+   * Interrupteur global de la bande des thèmes (bouton du header).
+   * Persisté : '0' = masquée partout, toute autre valeur = visible
+   * (sous réserve des règles de route : jamais sur /watch, etc.).
+   */
+  private static readonly BAR_VISIBLE_KEY = 'newtube.themesBarVisible';
+  readonly barVisible = signal<boolean>((() => {
+    try { return localStorage.getItem(ThemesService.BAR_VISIBLE_KEY) !== '0'; } catch { return true; }
+  })());
+
+  setBarVisible(v: boolean): void {
+    this.barVisible.set(!!v);
+    try { localStorage.setItem(ThemesService.BAR_VISIBLE_KEY, v ? '1' : '0'); } catch {}
+  }
+
+  toggleBarVisible(): void {
+    this.setBarVisible(!this.barVisible());
+  }
+
   constructor(private i18n: I18nService) {}
 
   themes() { return this.list(); }