Document env vars and remove theme collapse button

- Expand .env.example with full runtime, cache, Docker, and AI keys
- Add deployment secrets to .gitignore (docker-compose/.env,
  docker/.registry.env)
- Remove VIMEO_ACCESS_TOKEN from compose files; add OAuth redirect URIs
- Load registry credentials from .registry.env in deploy-img.sh
- Fail fast if protected registry lacks auth during pre-checks
- Pass DOCKER_USERNAME/PASSWORD explicitly to WSL in deploy-img.ps1
- Remove inline collapse buttons from themes-nav.component.html

src/components/themes/themes-nav.component.html

@@ -39,18 +39,7 @@
     »
   </button>
 
-  <!-- Replier la bande -->
-  <button type="button" (click)="toggleCollapsed()" [attr.aria-expanded]="true" aria-controls="themes-bar"
-          [title]="'themes.hide' | t : 'Masquer la bande des thèmes'"
-          class="absolute right-12 top-1/2 z-10 hidden h-9 w-9 -translate-y-1/2 items-center justify-center rounded-full shadow transition focus:outline-none focus-visible:ring-2 focus-visible:ring-red-500 md:flex"
-          [ngClass]="{
-            'bg-white/90 border border-slate-300 text-slate-700 hover:bg-slate-100': isLightTheme(),
-            'bg-slate-800/90 border border-slate-700 text-slate-200 hover:bg-slate-700': isDarkTheme() || isBlackTheme() || isBlueTheme()
-          }"
-          aria-label="Masquer la bande des thèmes">
-    <svg xmlns="http://www.w3.org/2000/svg" class="h-4 w-4" viewBox="0 0 20 20" fill="currentColor" aria-hidden="true"><path fill-rule="evenodd" d="M14.707 12.707a1 1 0 01-1.414 0L10 9.414l-3.293 3.293a1 1 0 01-1.414-1.414l4-4a1 1 0 011.414 0l4 4a1 1 0 010 1.414z" clip-rule="evenodd" /></svg>
-  </button>
-
+  <!-- Replier la bande : action disponible uniquement dans le header -->
   <div class="w-full overflow-x-auto no-scrollbar" #scroll (wheel)="onWheel($event)">
     <ul role="tablist" aria-label="Themes" class="flex gap-2 px-12 py-2 min-w-max items-center">
       <li *ngFor="let t of displayedThemes(); let i = index" class="shrink-0">
@@ -72,12 +61,6 @@
           <span>{{ themesSvc.i18nLabel(t) }}</span>
         </button>
       </li>
-      <li class="shrink-0 md:hidden">
-        <button type="button" (click)="toggleCollapsed()"
-                class="px-3 py-1.5 rounded-full text-xs font-semibold text-slate-400 border border-slate-700 whitespace-nowrap">
-          {{ 'themes.hide' | t : 'Masquer' }}
-        </button>
-      </li>
     </ul>
   </div>
 </nav>