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>

.woodpecker.yml

@@ -0,0 +1,28 @@
+when:
+  branch: main
+  event: [push, manual]
+
+steps:
+  - name: build
+    image: docker:cli
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+    commands:
+      - docker build -t yugioh-api:latest .
+
+  - name: deploy
+    image: docker:cli
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+      - /opt/docker/yugioh/.env:/opt/docker/yugioh/.env
+    commands:
+      - sed "s/='\(.*\)'$/=\1/; s/=\"\(.*\)\"$/=\1/" /opt/docker/yugioh/.env > /tmp/yugioh-api.env
+      - docker stop yugioh-api || true
+      - docker rm yugioh-api || true
+      - docker network create yugioh || true
+      - docker run -d
+          --name yugioh-api
+          --restart unless-stopped
+          --network yugioh
+          --env-file /tmp/yugioh-api.env
+          yugioh-api:latest