fix(mpc-service): 使用 openssl 包替代 openssl1.1-compat

Alpine 3.22 已移除 openssl1.1-compat
使用 openssl (OpenSSL 3) 替代

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

backend/services/mpc-service/Dockerfile

@@ -30,8 +30,8 @@ FROM node:20-alpine
 
 WORKDIR /app
 
-# Install OpenSSL 1.1 for Prisma
-RUN apk add --no-cache openssl1.1-compat
+# Install OpenSSL for Prisma (Alpine 3.22 uses OpenSSL 3)
+RUN apk add --no-cache openssl
 
 # Install production dependencies only
 COPY package*.json ./