fix: Update CI/CD pipeline for Next.js

- Updated Gitea workflow to build Next.js instead of Nuxt
- Removed working-directory references to apps/website
- Created Dockerfile for Next.js production builds
- Added standalone output mode to next.config.js for Docker
- Updated build and artifact paths in workflow

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

next.config.js

@@ -1,6 +1,7 @@
 /** @type {import('next').NextConfig} */
 const nextConfig = {
   reactStrictMode: true,
+  output: 'standalone',
   images: {
     domains: ['videos.pexels.com'],
   },