Add Docker, Woodpecker CI/CD, and cleanup

- Add Dockerfile and .dockerignore for containerisation
- Add .woodpecker.yml pipeline (build + deploy to yugioh network on .101)
- Add .gitignore to stop tracking .env; replace with .env.example
- Add npm start script
- Fix index.js: move versionRoutes require before listen, add /health endpoint
- Fix git remote push URLs (were pointing at Dashboard repo)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.dockerignore

@@ -0,0 +1,3 @@
+node_modules
+.env
+.git