feat: PWA支持（manifest+Service Worker缓存+图标，可添加到主屏幕/离线/增量更新）

static/manifest.json

@@ -0,0 +1,17 @@
+{
+  "name": "VPS 资产管理系统",
+  "short_name": "资产管理",
+  "description": "个人数字资产管理：VPS、域名、AI 账号、Cloudflare，续费提醒与状态监控",
+  "start_url": "/",
+  "scope": "/",
+  "display": "standalone",
+  "background_color": "#0f172a",
+  "theme_color": "#2563eb",
+  "orientation": "any",
+  "lang": "zh-CN",
+  "icons": [
+    { "src": "/static/icons/icon-192.png", "sizes": "192x192", "type": "image/png", "purpose": "any" },
+    { "src": "/static/icons/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any" },
+    { "src": "/static/icons/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "maskable" }
+  ]
+}

static/sw.js

@@ -0,0 +1,63 @@
+/* vps-manager Service Worker
+ * 缓存策略：
+ *  - 预缓存核心静态资源，安装即可离线打开
+ *  - 静态资源与页面：stale-while-revalidate（先返回缓存秒开，后台自动拉取最新版本）
+ *  - /api/* 数据请求：始终走网络，保证数据实时
+ * 更新机制：业务代码更新后，后台自动同步到缓存，下次访问生效；
+ *           若需强制刷新缓存，递增 CACHE_NAME 即可清理旧缓存。
+ */
+const CACHE_NAME = 'vps-manager-v1';
+
+const PRECACHE_URLS = [
+  '/',
+  '/static/js/vue.global.prod.js',
+  '/static/js/tailwind.js',
+  '/static/js/api.js',
+  '/static/js/app.js',
+  '/static/manifest.json',
+  '/static/icons/icon-192.png',
+  '/static/icons/icon-512.png',
+];
+
+self.addEventListener('install', (event) => {
+  event.waitUntil(
+    caches
+      .open(CACHE_NAME)
+      .then((cache) => cache.addAll(PRECACHE_URLS))
+      .then(() => self.skipWaiting())
+  );
+});
+
+self.addEventListener('activate', (event) => {
+  event.waitUntil(
+    caches
+      .keys()
+      .then((keys) =>
+        Promise.all(keys.filter((k) => k !== CACHE_NAME).map((k) => caches.delete(k)))
+      )
+      .then(() => self.clients.claim())
+  );
+});
+
+self.addEventListener('fetch', (event) => {
+  const request = event.request;
+  if (request.method !== 'GET') return;
+
+  const url = new URL(request.url);
+  if (url.origin !== self.location.origin) return;
+  // 数据接口走网络，不缓存
+  if (url.pathname.startsWith('/api/')) return;
+
+  event.respondWith(
+    caches.open(CACHE_NAME).then(async (cache) => {
+      const cached = await cache.match(request);
+      const network = fetch(request)
+        .then((response) => {
+          if (response && response.ok) cache.put(request, response.clone());
+          return response;
+        })
+        .catch(() => cached);
+      return cached || network;
+    })
+  );
+});