docs(playground) : exemples required + email lowercase

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.playground/pages/composant/select/select.vue

@@ -82,6 +82,17 @@
       />
     </div>
 
+    <div class="rounded-lg border p-4">
+      <h2 class="mb-4 text-xl font-bold">Sélection obligatoire</h2>
+      <MalioSelect
+        v-model="requiredValue"
+        :options="options"
+        label="Sélection obligatoire"
+        :required="true"
+        empty-option-label="Aucune selection"
+      />
+    </div>
+
     <div class="rounded-lg border p-4">
       <h2 class="mb-4 text-xl font-bold">Peu d'elements (2)</h2>
       <MalioSelect
@@ -151,6 +162,7 @@ const longOptions = [
   {label: 'Republique tcheque', value: 'cz'},
 ]
 
+const requiredValue = ref<string | number | null>(null)
 const basicValue = ref<string | number | null>(null)
 const labelValue = ref<string | number | null>(null)
 const selectedValue = ref<string | number | null>('fr')