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>

agent/app/security/approval.py

@@ -0,0 +1,104 @@
+"""
+审批服务 - 处理工具执行的审批流程
+"""
+import uuid
+from datetime import datetime
+from typing import Any, Dict, Optional
+from enum import Enum
+
+
+class ApprovalStatus(Enum):
+    """审批状态"""
+    PENDING = "pending"
+    APPROVED = "approved"
+    REJECTED = "rejected"
+
+
+class ApprovalService:
+    """审批服务"""
+
+    def __init__(self):
+        # 待审批队列
+        self.pending: Dict[str, dict] = {}
+        # 审批结果
+        self.results: Dict[str, ApprovalStatus] = {}
+
+    async def request_approval(
+        self,
+        tool_name: str,
+        params: dict,
+        user_id: str,
+        agent_id: str,
+        reason: str
+    ) -> str:
+        """
+        请求审批
+
+        Returns:
+            request_id: 审批请求ID
+        """
+        request_id = str(uuid.uuid4())
+
+        request = {
+            "request_id": request_id,
+            "tool_name": tool_name,
+            "params": params,
+            "user_id": user_id,
+            "agent_id": agent_id,
+            "reason": reason,
+            "status": ApprovalStatus.PENDING,
+            "created_at": datetime.now().isoformat()
+        }
+
+        self.pending[request_id] = request
+        self.results[request_id] = ApprovalStatus.PENDING
+
+        # TODO: 通知 Go 后端有新审批
+
+        return request_id
+
+    async def check_approval(self, request_id: str, timeout: int = 300) -> bool:
+        """
+        检查审批状态
+
+        Args:
+            request_id: 审批请求ID
+            timeout: 超时时间（秒）
+
+        Returns:
+            是否已批准
+        """
+        import asyncio
+
+        start = datetime.now()
+
+        while (datetime.now() - start).seconds < timeout:
+            status = self.results.get(request_id)
+
+            if status == ApprovalStatus.APPROVED:
+                return True
+            elif status == ApprovalStatus.REJECTED:
+                return False
+
+            await asyncio.sleep(1)
+
+        raise TimeoutError("Approval request timeout")
+
+    async def approve(self, request_id: str):
+        """批准请求"""
+        if request_id in self.pending:
+            self.pending[request_id]["status"] = ApprovalStatus.APPROVED
+            self.results[request_id] = ApprovalStatus.APPROVED
+
+    async def reject(self, request_id: str):
+        """拒绝请求"""
+        if request_id in self.pending:
+            self.pending[request_id]["status"] = ApprovalStatus.REJECTED
+            self.results[request_id] = ApprovalStatus.REJECTED
+
+    def get_pending(self) -> list[dict]:
+        """获取待审批列表"""
+        return [
+            req for req in self.pending.values()
+            if req["status"] == ApprovalStatus.PENDING
+        ]