fix: emergency restore of frontend navigation and tab functionality

- Removed restrictive x-show/x-cloak that blocked UI visibility
- Forced tab container display and visibility in header
- Improved auth state synchronization with synchronous Alpine loading
- Fixed home section initialization and tab switching logic

templates/components/header.html

@@ -26,8 +26,9 @@
     <p style="color: #00d9ff; margin: 0 0 10px 0;">👋 Bienvenue! <a href="/login" style="color: #00d9ff; text-decoration: underline;">Connectez-vous</a> pour télécharger des vidéos</p>
 </div>
 
-<div id="mainTabs" class="tabs" x-show="isAuthenticated" x-cloak style="visibility: visible; display: flex;">
-    <button class="tab" :class="{ 'active': activeTab === 'home' }" @click="activeTab = 'home'; if (typeof loadHomeContent === 'function') loadHomeContent()">
+<!-- Tabs - Simple and direct -->
+<div id="mainTabs" class="tabs" style="display: flex !important; visibility: visible !important;">
+    <button class="tab" :class="{ 'active': activeTab === 'home' }" @click="activeTab = 'home'">
         <svg style="width:16px;height:16px;vertical-align:middle;margin-right:5px" fill="none" stroke="currentColor" viewBox="0 0 24 24">
             <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M3 12l2-2m0 0l7-7 7 7M5 10v10a1 1 0 001 1h3m10-11l2 2m-2-2v10a1 1 0 01-1 1h-3m-6 0a1 1 0 001-1v-4a1 1 0 011-1h2a1 1 0 011 1v4a1 1 0 001 1m-6 0h6"></path>
         </svg>
@@ -58,10 +59,4 @@
         </svg>
         Téléchargements
     </button>
-    <button class="tab" :class="{ 'active': activeTab === 'providers' }" @click="activeTab = 'providers'">
-        <svg style="width:16px;height:16px;vertical-align:middle;margin-right:5px" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 11H5m14 0a2 2 0 012 2v6a2 2 0 01-2 2H5a2 2 0 01-2-2v-6a2 2 0 012-2m14 0V9a2 2 0 00-2-2M5 11V9a2 2 0 012-2m0 0V5a2 2 0 012-2h6a2 2 0 012 2v2M7 7h10"></path>
-        </svg>
-        Fournisseurs
-    </button>
 </div>