feat: 增强SaaS后端功能与安全性

refactor: 重构数据库连接使用PostgreSQL替代SQLite
feat(auth): 增加JWT验证的audience和issuer检查
feat(crypto): 添加AES-256-GCM字段加密支持
feat(api): 集成utoipa实现OpenAPI文档
fix(admin): 修复配置项表单验证逻辑
style: 统一代码格式与类型定义
docs: 更新技术栈文档说明PostgreSQL

Makefile

@@ -1,7 +1,9 @@
 # ZCLAW Makefile
 # Cross-platform task runner
 
-.PHONY: help start start-dev start-no-browser desktop desktop-build setup test clean
+.PHONY: help start start-dev start-no-browser desktop desktop-build setup test clean \
+        saas-build saas-run saas-test saas-test-integration saas-clippy saas-migrate \
+        saas-docker-up saas-docker-down saas-docker-build
 
 help: ## Show this help message
 	@echo "ZCLAW - AI Agent Desktop Client"
@@ -71,3 +73,32 @@ clean-deep: clean ## Deep clean (including pnpm cache)
 	@rm -rf desktop/pnpm-lock.yaml
 	@rm -rf pnpm-lock.yaml
 	@echo "Deep clean complete. Run 'pnpm install' to reinstall."
+
+# === SaaS Backend ===
+
+saas-build: ## Build zclaw-saas crate
+	@cargo build -p zclaw-saas
+
+saas-run: ## Start SaaS backend (cargo run)
+	@cargo run -p zclaw-saas
+
+saas-test: ## Run SaaS unit tests
+	@cargo test -p zclaw-saas -- --test-threads=1
+
+saas-test-integration: ## Run SaaS integration tests (requires PostgreSQL)
+	@cargo test -p zclaw-saas -- --ignored --test-threads=1
+
+saas-clippy: ## Run clippy on zclaw-saas
+	@cargo clippy -p zclaw-saas -- -D warnings
+
+saas-migrate: ## Run database migrations
+	@cargo run -p zclaw-saas -- --migrate
+
+saas-docker-up: ## Start SaaS services (PostgreSQL + backend)
+	@docker compose up -d
+
+saas-docker-down: ## Stop SaaS services
+	@docker compose down
+
+saas-docker-build: ## Build SaaS Docker images
+	@docker compose build