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>

package.json

@@ -4,6 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
+    "start": "node src/index.js",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "repository": {