feat: 重构前后端架构，添加Go后端和Python Agent服务

- 新增 Go 语言后端服务(server/)，包含用户认证、Agent管理、数据库连接等API
- 新增 Python Agent 服务(agent/)，实现Agent核心逻辑和工具集
- 前端从原生HTML迁移到Vue.js框架(web/src/)
- 添加 Docker Compose 支持(docker-compose.yml)
- 添加项目架构文档(docs/ARCHITECTURE.md)
- 添加环境变量示例(.env.example)和本地启动脚本(start-local.ps1)

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

docker-compose.dev.yml

@@ -0,0 +1,33 @@
+services:
+  # MySQL 数据库
+  x-agent-mysql:
+    image: mysql:8.0
+    container_name: x-agents-mysql
+    environment:
+      MYSQL_ROOT_PASSWORD: root
+      MYSQL_DATABASE: x_agents
+    volumes:
+      - mysql-data:/var/lib/mysql
+    ports:
+      - "6036:3306"
+    healthcheck:
+      test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+    restart: unless-stopped
+    command: --default-authentication-plugin=mysql_native_password
+
+  # Redis
+  x-agent-redis:
+    image: redis:7-alpine
+    container_name: x-agents-redis
+    ports:
+      - "6037:6379"
+    volumes:
+      - redis-data:/data
+    restart: unless-stopped
+
+volumes:
+  mysql-data:
+  redis-data: