chore(dev): add /api proxy and docs

next.config.ts

@@ -1,5 +1,22 @@
 import type { NextConfig } from "next"
 
-const nextConfig: NextConfig = {}
+const nextConfig: NextConfig = {
+  async rewrites() {
+    // 仅在开发环境启用 API 代理
+    if (process.env.NODE_ENV !== "development") {
+      return []
+    }
+
+    const backendUrl =
+      process.env.NEXT_PUBLIC_BACKEND_URL || "http://localhost:8080"
+
+    return [
+      {
+        source: "/api/:path*",
+        destination: `${backendUrl}/api/:path*`,
+      },
+    ]
+  },
+}
 
 export default nextConfig