fix: switch admin to subdomain mode and fix frozen-lockfile build

- Remove /admin path prefix (using admin.protdskj.top subdomain instead)
- Change pnpm install to --no-frozen-lockfile for lockfile compatibility
- Simplify admin Nginx config to standard SPA serving

🤖 Generated with [Qoder][https://qoder.com]

apps/admin/vite.config.ts

@@ -3,7 +3,6 @@ import vue from '@vitejs/plugin-vue';
 import { resolve } from 'path';
 
 export default defineConfig({
-  base: '/admin/',
   plugins: [vue()],
   resolve: {
     // 避免 src 内遗留的 .js 抢先于 .ts/.vue 被解析（曾导致 i18n 文案缺失）
@@ -16,12 +15,6 @@ export default defineConfig({
   publicDir: resolve(__dirname, '../../packages/shared/public'),
   server: {
     port: 5174,
-    proxy: {
-      '/admin/api': {
-        target: 'http://localhost:3000',
-        changeOrigin: true,
-        rewrite: (path) => path.replace(/^\/admin\/api/, '/api'),
-      },
-    },
+    proxy: { '/api': { target: 'http://localhost:3000', changeOrigin: true } },
   },
 });