feat: 平台同步状态记录（last_synced_at + 前端展示最后同步时间）

static/js/app.js

@@ -315,6 +315,7 @@ const ProvidersView = {
             <span v-else class="text-slate-400">未配置 API</span>
             <span :class="p.enabled ? 'text-emerald-600 dark:text-emerald-400' : 'text-slate-400'">{{ p.enabled ? '启用' : '停用' }}</span>
           </div>
+          <div v-if="p.last_synced_at" class="text-slate-400">最后同步：{{ fmtTime(p.last_synced_at) }}</div>
         </div>
         <div class="flex gap-4 mt-3 pt-2 border-t border-slate-100 dark:border-slate-800 text-xs flex-wrap">
           <button @click="edit(p)" class="text-blue-600 dark:text-blue-400">编辑</button>
@@ -335,6 +336,10 @@ const ProvidersView = {
       try { const r = await Api.get('/providers/adapters'); supported.value = r.supported_types || []; } catch (e) { /* ignore */ }
     });
     function isSupported(t) { return !!t && supported.value.includes(t); }
+    function fmtTime(iso) {
+      if (!iso) return '';
+      return new Date(iso).toLocaleString('zh-CN', { month: '2-digit', day: '2-digit', hour: '2-digit', minute: '2-digit' });
+    }
     async function test(p) {
       testing[p.id] = true; delete results[p.id];
       try {
@@ -358,7 +363,7 @@ const ProvidersView = {
       } catch (e) { results[p.id] = { ok: false, text: '✗ ' + e.message }; }
       finally { syncing[p.id] = false; }
     }
-    return { store, Fmt, testing, syncing, results, isSupported, test, sync, seed: seedProviders, create: openProviderCreate, edit: openProviderEdit, del: deleteProvider };
+    return { store, Fmt, testing, syncing, results, isSupported, fmtTime, test, sync, seed: seedProviders, create: openProviderCreate, edit: openProviderEdit, del: deleteProvider };
   },
 };