fix(snapshot): Dockerfile 添加 ca-certificates 修复 mc 下载 SSL 错误

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/services/snapshot-service/Dockerfile

@@ -21,6 +21,7 @@ WORKDIR /app
 RUN apt-get update && apt-get install -y --no-install-recommends \
     openssl \
     curl \
+    ca-certificates \
     postgresql-client \
     && rm -rf /var/lib/apt/lists/*