Add Node.js Hello World application with Docker support

- Added index.js: Simple HTTP server on port 3000
- Added package.json: NPM configuration
- Added Dockerfile: Multi-stage Docker build
- Added .dockerignore: Exclude unnecessary files from build

Ready for Coolify deployment via CI/CD pipeline.

.dockerignore

@@ -0,0 +1,5 @@
+node_modules
+npm-debug.log
+.git
+.gitignore
+README.md