feat(api): update API configuration and add proxy rewrites

- Remove the NEXT_PUBLIC_API_URL from the production environment file.
- Change axios base URL to use a local proxy endpoint.
- Add rewrites in next.config.mjs to route API requests through the proxy.

next.config.mjs

@@ -6,25 +6,33 @@ const nextConfig = {
       {
         protocol: "https",
         hostname: "cdn.sanity.io",
-        port: ""
+        port: "",
       },
       {
         protocol: "https",
         hostname: "lh3.googleusercontent.com",
-        port: ""
+        port: "",
       },
       {
         protocol: "https",
         hostname: "avatars.githubusercontent.com",
-        port: ""
+        port: "",
       },
       {
         protocol: "https",
         hostname: "pub-b7fd9c30cdbf439183b75041f5f71b92.r2.dev",
-        port: ""
-      }
-    ]
-  }
+        port: "",
+      },
+    ],
+  },
+  async rewrites() {
+    return [
+      {
+        source: "/api/proxy/:path*",
+        destination: `https://admin.opplenz.com/admin/v1/:path*`,
+      },
+    ];
+  },
 };
 
 export default nextConfig;