feat: add global manual sync button in admin header

frontend/src/App.vue

@@ -12,7 +12,15 @@
           <NavTab v-for="tab in adminTabs" :key="tab.to" :to="tab.to">{{ tab.label }}</NavTab>
         </nav>
 
-        <div class="flex-shrink-0 ml-4">
+        <div class="flex-shrink-0 ml-4 flex items-center gap-2">
+          <button
+            v-if="showManualSync"
+            @click="handleManualSync"
+            :disabled="syncing"
+            class="text-xs text-blue-600 border border-blue-200 hover:border-blue-300 hover:bg-blue-50 transition-colors px-2 py-1 rounded disabled:opacity-60 disabled:cursor-not-allowed"
+          >
+            {{ syncing ? '同步中...' : '手動同步' }}
+          </button>
           <button
             @click="logout"
             class="text-xs text-gray-400 hover:text-gray-600 transition-colors px-2 py-1 rounded hover:bg-gray-100"
@@ -30,13 +38,16 @@
 </template>
 
 <script setup>
-import { computed, defineComponent, h } from 'vue'
+import { computed, defineComponent, h, ref } from 'vue'
 import { useRoute, useRouter, RouterLink } from 'vue-router'
+import { ElMessage } from 'element-plus'
+import { adminHttp } from '@/api/http'
 import { useAuthStore } from '@/stores/auth'
 
 const route = useRoute()
 const router = useRouter()
 const authStore = useAuthStore()
+const syncing = ref(false)
 
 const showNav = computed(() => {
   const onAuthPage = route.name === 'login' || route.name === 'auth-callback'
@@ -48,6 +59,8 @@ const userTabs = [
   { to: '/me/permissions', label: '我的角色' }
 ]
 
+const showManualSync = computed(() => route.path.startsWith('/admin'))
+
 const adminTabs = [
   { to: '/admin/companies', label: '公司' },
   { to: '/admin/sites', label: '站台' },
@@ -78,4 +91,21 @@ function logout() {
   authStore.logout()
   router.push('/login')
 }
+
+async function handleManualSync() {
+  if (syncing.value) return
+  syncing.value = true
+  try {
+    const res = await adminHttp.post('/admin/sync/from-provider', null, { params: { force: true } })
+    const data = res?.data || {}
+    ElMessage.success(
+      `同步完成: 系統+${data.systems_created || 0}/${data.systems_updated || 0}, 角色+${data.roles_created || 0}/${data.roles_updated || 0}`
+    )
+  } catch (err) {
+    const detail = err?.response?.data?.detail || err?.message || 'sync_failed'
+    ElMessage.error(`同步失敗：${detail}`)
+  } finally {
+    syncing.value = false
+  }
+}
 </script>