docs: 创建专业的项目 README 文档

详细说明:
- 添加完整的项目介绍和架构说明
- 包含 7 个 AI Agent 的详细介绍
- 添加技术栈和 Mermaid 架构图
- 完善安装和使用指南
- 添加开发指南和 Git 工作流
- 新增 Windows 快速部署文档
- 更新前端组件和启动脚本
- 添加多种环境配置文件

修改的文件:
- 新增 README.md 主文档
- 新增 doc/ 目录及部署文档
- 更新前端演示系统组件
- 添加多个启动脚本变体
- 配置文件优化

影响的功能模块:
- 项目文档体系
- 部署和启动流程
- 前端展示系统
- 环境配置管理

n8n-n8n-1.109.2/n8n-demo-20250911-172936.log

@@ -0,0 +1,22 @@
+
+> n8n-monorepo@1.109.2 start /Users/xiaoqi/Documents/Dev/Project/2025-09-08_n8nDEMO演示/n8n-n8n-1.109.2
+> run-script-os
+
+
+> n8n-monorepo@1.109.2 start:default
+> cd packages/cli/bin && ./n8n
+
+
+/Users/xiaoqi/Documents/Dev/Project/2025-09-08_n8nDEMO演示/n8n-n8n-1.109.2/packages/core/src/instance-settings/instance-settings.ts:227
+			.update(encryptionKey.slice(Math.round(encryptionKey.length / 2)))
+                         ^
+TypeError: Cannot read properties of undefined (reading 'slice')
+    at InstanceSettings.generateInstanceId (/Users/xiaoqi/Documents/Dev/Project/2025-09-08_n8nDEMO演示/n8n-n8n-1.109.2/packages/core/src/instance-settings/instance-settings.ts:227:26)
+    at new InstanceSettings (/Users/xiaoqi/Documents/Dev/Project/2025-09-08_n8nDEMO演示/n8n-n8n-1.109.2/packages/core/src/instance-settings/instance-settings.ts:68:26)
+    at ContainerClass.get (/Users/xiaoqi/Documents/Dev/Project/2025-09-08_n8nDEMO演示/n8n-n8n-1.109.2/packages/@n8n/di/src/di.ts:104:16)
+    at CommunityPackagesModule.loadDir (/Users/xiaoqi/Documents/Dev/Project/2025-09-08_n8nDEMO演示/n8n-n8n-1.109.2/packages/cli/src/modules/community-packages/community-packages.module.ts:37:30)
+    at processTicksAndRejections (node:internal/process/task_queues:105:5)
+    at ModuleRegistry.loadModules (/Users/xiaoqi/Documents/Dev/Project/2025-09-08_n8nDEMO演示/n8n-n8n-1.109.2/packages/@n8n/backend-common/src/modules/module-registry.ts:92:20)
+    at CommandRegistry.execute (/Users/xiaoqi/Documents/Dev/Project/2025-09-08_n8nDEMO演示/n8n-n8n-1.109.2/packages/cli/src/command-registry.ts:43:3)
+    at /Users/xiaoqi/Documents/Dev/Project/2025-09-08_n8nDEMO演示/n8n-n8n-1.109.2/packages/cli/bin/n8n:63:2
+ ELIFECYCLE  Command failed with exit code 1.