feat: update modern nginx conf for backend and frontend

assets/legacy.nginx.conf

@@ -1,5 +1,5 @@
 
-# Setup this path to coconut-legacy frontend.
+# Setup this path to coconut-leaf legacy frontend.
 set $frontend_root /var/www/coconut-leaf/frontend-legacy;
 root $frontend_root;
 index home.html;

assets/modern.nginx.conf

@@ -1,60 +1,63 @@
+
+# Setup this path to coconut-leaf frontend.
+set $frontend_root /var/www/coconut-leaf/frontend/dist;
+
 # ============================
-# 路由 1: /web -> 静态文件
+# Route 1: /web -> Vite-built SPA
 # ============================
 location /web {
-	# 使用 alias 精确映射
+	alias $frontend_root;
-	# 请求 /web/index.html -> /var/www/static/index.html
+	index index.html;
-	alias /var/www/static;
 
-	# 静态文件优化
+	# Optimize for static file
 	expires 7d;
 	add_header Cache-Control "public, max-age=604800";
-	
-	# 尝试返回文件，不存在则返回404（避免落入其他location）
-	try_files $uri $uri/ =404;
-	
-	# 可选：启用 gzip 压缩
 	gzip_static on;
+
+	# SPA fallback: for non-file routes, serve index.html
+	try_files $uri $uri/ /web/index.html;
 }
 
 # ============================
-# 路由 2: /api -> Go 程序 (8848端口)
+# Route 3: /api -> reverse proxy to backend
 # ============================
 location /api {
-	# 反向代理到本地 Go 服务
+	# Rewrite to remove "api" prefix
+	rewrite ^/api(/.*)$ $1 break;
+
+	# Reverse proxy to localhost backend
 	proxy_pass http://127.0.0.1:8848;
 
-	# 重要：保留原始请求头
+	# Keep original request headers
 	proxy_set_header Host $host;
 	proxy_set_header X-Real-IP $remote_addr;
 	proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 	proxy_set_header X-Forwarded-Proto $scheme;
 
-	# WebSocket 支持（如果 Go 程序需要）
+	# Optional: WebSocket support
 	# proxy_http_version 1.1;
 	# proxy_set_header Upgrade $http_upgrade;
 	# proxy_set_header Connection "upgrade";
 	
-	# 超时设置（根据业务调整）
+	# Time configuration
 	proxy_connect_timeout 60s;
 	proxy_send_timeout 60s;
 	proxy_read_timeout 60s;
 
-	# 缓冲设置（可选，大文件上传时注意调整）
+	# Buffer setup (changed when meeting large file uploading)
 	proxy_buffering on;
 	proxy_buffer_size 4k;
 	proxy_buffers 8 4k;
 }
 
 # ============================
-# 可选：根路径处理
+# Root path redirect: Root -> /web/home
 # ============================
 location = / {
-	# 重定向到 /web
+	return 302 /web/home;
-	return 302 /web/;
 }
 
-# 禁止访问隐藏文件
+# Deny hidden files at root level
 location ~ /\. {
 	deny all;
 	return 404;