feat: 新增 Docker Compose 部署方案

- Dockerfile 单阶段 Alpine 镜像，使用国内镜像（npmmirror / Prisma 引擎 / apk）加速
- entrypoint 首次复制内置图章素材到 uploads volume，自动执行 prisma migrate deploy
- docker-compose.yml 绑定 127.0.0.1:3001，强制走外部 Nginx 反代
- Express 在 production 下同时托管 packages/web/dist 及 SPA fallback
- Prisma schema 增加 linux-musl 二进制目标，支持 Alpine 运行
- 新增 DEPLOY.md 部署指南，含 .env 模板与 Nginx 反代示例

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

Dockerfile

@@ -0,0 +1,44 @@
+FROM node:22-alpine
+
+WORKDIR /app
+
+# 国内构建环境加速（仅容器构建期生效，不影响本地/正式 registry）
+# 1) Alpine apk 源换清华
+RUN sed -i 's|https\?://dl-cdn.alpinelinux.org|https://mirrors.tuna.tsinghua.edu.cn|g' /etc/apk/repositories
+
+RUN corepack enable && corepack prepare pnpm@9 --activate \
+  && apk add --no-cache openssl
+
+# 2) npm / pnpm registry 换淘宝镜像
+# 3) Prisma 下载引擎走淘宝镜像
+ENV PRISMA_ENGINES_MIRROR=https://registry.npmmirror.com/-/binary/prisma
+RUN npm config set registry https://registry.npmmirror.com/ \
+  && pnpm config set registry https://registry.npmmirror.com/
+
+# Copy everything (.dockerignore filters out node_modules, dist, .git, etc.)
+COPY . .
+
+# 强制项目级 registry（兜底：防止项目根 .npmrc 未覆盖）
+RUN echo "registry=https://registry.npmmirror.com/" > /app/.npmrc
+
+# Install all deps (tsx is used at runtime via devDependencies)
+RUN pnpm install --frozen-lockfile --registry=https://registry.npmmirror.com/
+
+# Generate Prisma client (produces linux-musl binary per schema.prisma)
+RUN pnpm exec prisma generate
+
+# Build web SPA; server runs directly from TS via tsx
+RUN pnpm --filter @stamp/web build
+
+# Stash initial stamp assets so the uploads volume can be seeded on first run
+RUN mkdir -p /app/stamps-seed \
+  && cp packages/server/uploads/stamps/*.jpg /app/stamps-seed/ \
+  && rm -rf packages/server/uploads/stamps
+
+COPY docker/entrypoint.sh /usr/local/bin/entrypoint.sh
+RUN chmod +x /usr/local/bin/entrypoint.sh
+
+ENV NODE_ENV=production
+EXPOSE 3000
+
+ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]