fix: nginx /assets 路由 403 修复 — 静态缓存改为正则匹配文件扩展名

/assets/ location 会拦截 SPA 路由 /assets（资产页），导致刷新 403。
改为正则匹配 /assets/*.{js,css,png,...}，只缓存实际静态文件，
不影响 SPA fallback 到 index.html。

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web/nginx.conf

@@ -24,8 +24,9 @@ server {
         client_max_body_size 50m;
     }
 
-    # Cache static assets (must be before SPA fallback)
-    location /assets/ {
+    # Cache static assets (JS/CSS/images built by Vite into dist/assets/)
+    # Use regex to only match actual files with extensions, not bare /assets path
+    location ~* ^/assets/.+\.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot|mp4|webm)$ {
         expires 30d;
         add_header Cache-Control "public, immutable";
     }