chore: update Docker setup

- Replace lowercase dockerfile with proper Dockerfile
- Add .dockerignore for cleaner builds
- Add build.sh script
- Update docker-compose.yml: separate volumes for config, database, plugins; set restart policy to unless-stopped; remove deprecated version field

Dockerfile

@@ -0,0 +1,19 @@
+# Docker File for Open Ticket v4
+FROM node:22-alpine
+
+# /home/container keeps Pterodactyl panel compatibility
+WORKDIR /home/container
+
+# Install dependencies
+COPY --chown=node:node package*.json ./
+RUN npm install
+
+# Copy app source
+COPY --chown=node:node . .
+
+ENV NODE_ENV=production
+
+# Run as the built-in non-root node user
+USER node
+
+CMD ["node", "index.js"]