feat: 添加 Dockerfile 和入口脚本，优化容器启动过程和权限管理

Author: CharyeahOwO

Dockerfile

@@ -1,17 +1,19 @@
 FROM node:20-alpine
 
+RUN apk add --no-cache su-exec
+
 WORKDIR /app
 ENV NODE_ENV=production
 
 COPY package*.json ./
 RUN npm ci --omit=dev
 
 COPY . .
-RUN mkdir -p /app/public/images && chown -R node:node /app
-
-USER node
+RUN mkdir -p /app/public/images && chown -R node:node /app \
+  && chmod +x /app/docker-entrypoint.sh
 
 EXPOSE 3000
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
   CMD wget -qO- http://localhost:3000/image/health || exit 1
+ENTRYPOINT ["/app/docker-entrypoint.sh"]
 CMD ["npm", "start"]

docker-entrypoint.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+set -e
+
+# Fix volume permissions: ensure node user can write to images directory
+if [ -d /app/public/images ]; then
+  chown -R node:node /app/public/images 2>/dev/null || true
+fi
+
+# Run the main process as node user
+exec su-exec node "$@"