Add Docker support for optimized Next.js deployment

Introduces Docker configuration files to enable containerized builds
and streamlined deployment using a multi-stage strategy with
standalone Next.js output. Updates configuration to optimize image
size and leverage production best practices.

next.config.mjs

@@ -1,4 +1,6 @@
 /** @type {import('next').NextConfig} */
-const nextConfig = {};
+const nextConfig = {
+  output: 'standalone',
+};
 
 export default nextConfig;