Adds Docker setup and basic API endpoints

WHAT: Introduces Dockerfiles for development and production, Docker Compose configurations, a Makefile for common tasks, shell scripts for environment setup/teardown, a basic Express API with SQLite integration.
WHY: Enables easy setup and deployment of the application using Docker. Provides basic API endpoints for managing purchase items.
HOW:
- Creates `docker-compose.dev.yml` and `docker-compose.prod.yml` to define services and volumes.
- Introduces `Dockerfile.dev` and `Dockerfile.prod` to build container images with necessary dependencies.
- Adds `Makefile` with commands for building, running, and managing the application.
- Implements shell scripts for simplified Docker environment management.
- Sets up Express API with endpoints for CRUD operations on purchase items, using SQLite as the database.
- Uses `better-sqlite3` to connect and interact with the SQLite database.

scripts/prod-build.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+echo "[Dream-Machine] 生产镜像构建"
+echo "- 环境要求: 前端包 dist/ 已在宿主机构建完成"
+echo "- 目标平台: linux/amd64"
+
+SCRIPT_DIR=$(cd "$(dirname "$0")" && pwd)
+ROOT_DIR=$(cd "$SCRIPT_DIR/.." && pwd)
+
+if [ ! -d "$ROOT_DIR/dist" ]; then
+  echo "[错误] 未检测到 dist/。请先在宿主机运行: pnpm run build"
+  exit 1
+fi
+
+echo "[步骤] 安装并构建后端 (宿主机)"
+(cd "$ROOT_DIR/server" && pnpm install && pnpm run build)
+
+echo "[步骤] 构建生产镜像 (仅打包、禁止在容器内构建)"
+(cd "$ROOT_DIR/docker" && docker buildx build --platform linux/amd64 -f Dockerfile.prod -t dm-purchase-api:prod ..)
+
+echo "[完成] 镜像: dm-purchase-api:prod"
+
+