feat: open model details modal on hover and refine cards layout

- Add on-hover modal opening for model cards with debounce
- Keep click-to-open behavior as fallback
- Prevent accidental hover triggers while moving inside same card
- Convert models list to responsive grid layout
- Improve card visual feedback and helper text for interaction

app/web/templates/index.html

@@ -60,14 +60,17 @@
                 <!-- Models Section -->
                 <div class="bg-gray-800 rounded-lg border border-gray-700 p-6">
                     <div class="flex items-center justify-between mb-6">
-                        <h2 class="text-xl font-bold">Modelli Disponibili</h2>
+                        <div>
+                            <h2 class="text-xl font-bold">Modelli Disponibili</h2>
+                            <p class="text-xs text-gray-400 mt-1">Passa il mouse o clicca una card per aprire la modal dettagli.</p>
+                        </div>
                         <button id="refresh-btn" class="bg-purple-600 hover:bg-purple-700 px-4 py-2 rounded-lg text-sm font-medium transition">
                             🔄 Aggiorna
                         </button>
                     </div>
 
                     <!-- Models List -->
-                    <div id="models-container" class="space-y-4">
+                    <div id="models-container" class="grid grid-cols-1 md:grid-cols-2 xl:grid-cols-3 gap-4">
                         <div class="text-center py-8">
                             <div class="animate-spin inline-block w-8 h-8 border-4 border-gray-600 border-t-purple-500 rounded-full"></div>
                             <p class="text-gray-400 mt-4">Caricamento modelli...</p>