fix: docker timezone issue

Dockerfile

@@ -1,5 +1,11 @@
 FROM docker.hub.ipao.vip/alpine:3.20
 
+# Set timezone
+RUN apk add --no-cache tzdata && \
+    cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime && \
+    echo "Asia/Shanghai" > /etc/timezone && \
+    apk del tzdata
+
 COPY backend/build/app /app/qvyun
 COPY backend/config.prod.toml /app/config.toml
 COPY frontend/dist /app/dist