fix(components): improve generic types (#3331)

Co-authored-by: Benjamin Canac <canacb1@gmail.com>

docs/app/components/content/examples/select/SelectItemsAvatarExample.vue

@@ -1,4 +1,6 @@
 <script setup lang="ts">
+import type { SelectItem } from '@nuxt/ui'
+
 const items = ref([
   {
     label: 'benjamincanac',
@@ -23,13 +25,21 @@ const items = ref([
       src: 'https://github.com/noook.png',
       alt: 'noook'
     }
+  },
+  {
+    label: 'sandros94',
+    value: 'sandros94',
+    avatar: {
+      src: 'https://github.com/sandros94.png',
+      alt: 'sandros94'
+    }
   }
-])
+] satisfies SelectItem[])
 const value = ref(items.value[0]?.value)
 
 const avatar = computed(() => items.value.find(item => item.value === value.value)?.avatar)
 </script>
 
 <template>
-  <USelect v-model="value" :avatar="avatar" :items="items" class="w-48" />
+  <USelect v-model="value" :items="items" value-key="value" :avatar="avatar" class="w-48" />
 </template>