fix: 添加 tzdata 和容器时区配置，修复 Alpine 镜像缺少时区数据的问题

Dockerfile

@@ -10,7 +10,7 @@ RUN CGO_ENABLED=0 GOOS=linux go build -o server .
 
 FROM alpine:latest
 RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories && \
-    apk --no-cache add ca-certificates
+    apk --no-cache add ca-certificates tzdata
 
 WORKDIR /app
 COPY --from=builder /app/server .

docker-compose.yml

@@ -4,4 +4,6 @@ services:
     ports:
       - "8083:8083"
     env_file: .env
+    environment:
+      - TZ=Asia/Shanghai
     restart: unless-stopped