feat: Configure Next.js API proxy and update API base path to relative.

frontend/next.config.ts

@@ -1,7 +1,14 @@
 import type { NextConfig } from "next";
 
 const nextConfig: NextConfig = {
-  /* config options here */
+  async rewrites() {
+    return [
+      {
+        source: '/api/:path*',
+        destination: 'http://127.0.0.1:8000/api/:path*',
+      },
+    ]
+  },
 };
 
 export default nextConfig;

frontend/src/lib/api.ts

@@ -1,4 +1,4 @@
-const API_BASE = "http://localhost:8000/api";
+const API_BASE = "/api";
 
 export async function searchStock(query: string) {
     const res = await fetch(`${API_BASE}/search`, {