task-17(壳层/路由): 桌面端壳层响应式验收 + 浏览器验收基建

引入 @playwright/test(mdEdge 通道)，playwright.config 起 mock admin API + vite dev；
e2e 覆盖宽/窄屏自动折叠、折叠持久化、无横向溢出等 8 用例；workspace 边界扫描
排除测试专用 e2e/scripts/playwright.config。

admin-frontend-vue/playwright.config.ts

@@ -0,0 +1,35 @@
+import { defineConfig } from '@playwright/test'
+
+/**
+ * 浏览器验收：起 mock admin API(18100) + vite dev(5174, /api 代理到 mock)。
+ * 本地用已安装的 MS Edge(channel: msedge)运行，无需下载 Chromium。
+ */
+export default defineConfig({
+  testDir: './e2e',
+  timeout: 45_000,
+  expect: { timeout: 10_000 },
+  fullyParallel: false,
+  workers: 1,
+  retries: 0,
+  reporter: [['list']],
+  use: {
+    baseURL: 'http://127.0.0.1:5174',
+    channel: 'msedge',
+    headless: true,
+    viewport: { width: 1440, height: 900 },
+    locale: 'zh-CN',
+  },
+  webServer: [
+    {
+      command: 'node scripts/mock-admin-server.mjs',
+      port: 18100,
+      reuseExistingServer: true,
+    },
+    {
+      command: 'set VITE_API_TARGET=http://127.0.0.1:18100&& npm run dev',
+      port: 5174,
+      reuseExistingServer: true,
+      timeout: 120_000,
+    },
+  ],
+})