feat(admin) : move clients into admin page, remove standalone page

frontend/pages/admin.vue

@@ -19,6 +19,7 @@
         </div>
 
         <div class="mt-6">
+            <AdminClientTab v-if="activeTab === 'clients'" />
             <AdminEffortTab v-if="activeTab === 'efforts'" />
             <AdminPriorityTab v-if="activeTab === 'priorities'" />
             <AdminTypeTab v-if="activeTab === 'types'" />
@@ -31,6 +32,7 @@
 useHead({ title: 'Administration' })
 
 const tabs = [
+    { key: 'clients', label: 'Clients' },
     { key: 'efforts', label: 'Efforts' },
     { key: 'priorities', label: 'Priorités' },
     { key: 'types', label: 'Types' },
@@ -39,5 +41,5 @@ const tabs = [
 
 type TabKey = typeof tabs[number]['key']
 
-const activeTab = ref<TabKey>('efforts')
+const activeTab = ref<TabKey>('clients')
 </script>