fix: 快速扫描前端超时 30s→180s

快速扫描需要 SSH 连接 30+ 台 OLT 并解析入库，后端实测 61 秒，
Axios 默认 30 秒超时导致请求在前端被中断。

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/views/OltManage.vue

@@ -938,7 +938,7 @@ const dismissNewDevice = async (id) => {
 const runQuickScan = async () => {
   quickScanning.value = true
   try {
-    const { data } = await request.post('/olt/quick-scan')
+    const { data } = await request.post('/olt/quick-scan', null, { timeout: 180000 })
     quickScanResult.value = data
     quickScanVisible.value = true
   } catch (error) {