feat: add Zeabur deployment configuration

backend/.dockerignore

@@ -0,0 +1,19 @@
+node_modules
+npm-debug.log
+.env
+.env.local
+.env.*.local
+dist
+.git
+.gitignore
+*.md
+.DS_Store
+Thumbs.db
+*.log
+coverage
+.nyc_output
+.vscode
+.idea
+*.swp
+*.swo
+*~

backend/Dockerfile

@@ -0,0 +1,15 @@
+FROM node:20-alpine
+
+WORKDIR /app
+
+COPY package*.json ./
+
+RUN npm ci --only=production
+
+COPY . .
+
+RUN mkdir -p uploads/avatars temp
+
+EXPOSE 8000
+
+CMD ["node", "server.js"]