添加Docker部署配置：backend Dockerfile、Caddyfile、docker-compose.yml，支持腾云云服务器部署域名skin.khhao.com，使用Caddy反向代理 + HTTPS

Makefile

@@ -1,4 +1,4 @@
-.PHONY: start dev backend frontend install stop
+.PHONY: start dev backend frontend install stop docker-build docker-up docker-down
 
 # 一键启动前后端（推荐）
 start dev:
@@ -19,3 +19,22 @@ stop:
 	@-lsof -tiTCP:8080 -sTCP:LISTEN | xargs kill 2>/dev/null || true
 	@-lsof -tiTCP:5173 -sTCP:LISTEN | xargs kill 2>/dev/null || true
 	@echo "已尝试停止 8080 / 5173 端口服务"
+
+# Docker deployment targets
+docker-build:
+	@echo "Building backend Docker image..."
+	docker build -f Dockerfile.backend -t affiliate-backend:latest .
+	@echo "Frontend must be built separately: cd frontend && npm run build"
+	@echo "Then run: docker compose up -d --build"
+
+docker-up:
+	@echo "Starting services with docker-compose..."
+	docker compose up -d --build
+
+docker-down:
+	@echo "Stopping and removing containers..."
+	docker compose down
+
+docker-logs:
+	@echo "Showing backend and caddy logs..."
+	docker compose logs -f backend caddy