feat(agents): Phase 6 tool system refactoring

Phase 6.1: ToolRegistry infrastructure
- Add ToolManifest with ToolCategory, PermissionClass, SideEffectScope
- Add ToolRegistry singleton with register/get/unregister/list/search
- Add BaseTool abstract class with ReadTool/WriteTool/DBWriteTool/ExternalTool/NetworkTool subclasses
- Add migration layer for backward compatibility

Phase 6.2: Hook interception system
- Add HookType (PRE_TOOL_USE, POST_TOOL_USE, TOOL_ERROR, TOOL_SKIP)
- Add HookManager with singleton for hook registration
- Add HookExecutor for pre/post/error hook execution

Phase 6.3: Streaming execution
- Add StreamingToolExecutor with batch execution support

Phase 6.4: New builtin tools
- Add file_tools: GlobTool, GrepTool, ReadFileTool, WriteFileTool
- Add system_tools: BashTool, PowerShellTool
- Add dev_tools: LSPTools, GitTool
- Add collaboration_tools: TeamAgentTool, TaskBroadcastTool

Tests: 29 passed

backend/app/agents/tools/base.py

@@ -0,0 +1,161 @@
+"""工具基类 - 工具系统重构 Phase 6.1"""
+
+from abc import ABC, abstractmethod
+from typing import Any, Generic, TypeVar
+
+from app.agents.tools.manifest import (
+    PermissionClass,
+    SideEffectScope,
+    ToolCategory,
+    ToolManifest,
+)
+
+
+T = TypeVar("T")
+
+
+class BaseTool(ABC, Generic[T]):
+    """工具基类
+
+    提供工具的标准接口和默认实现。
+    所有自定义工具应继承此类。
+    """
+
+    def __init__(
+        self,
+        name: str,
+        description: str,
+        category: ToolCategory,
+        permission_class: PermissionClass,
+        side_effect_scope: SideEffectScope = SideEffectScope.NONE,
+        requires_confirmation: bool = False,
+        is_streaming: bool = False,
+        tags: list[str] | None = None,
+    ):
+        self.name = name
+        self.description = description
+        self.category = category
+        self.permission_class = permission_class
+        self.side_effect_scope = side_effect_scope
+        self.requires_confirmation = requires_confirmation
+        self.is_streaming = is_streaming
+        self.tags = tags or []
+
+    def get_manifest(self) -> ToolManifest:
+        """获取工具元数据
+
+        Returns:
+            工具元数据
+        """
+        return ToolManifest(
+            name=self.name,
+            description=self.description,
+            category=self.category,
+            parameters=self.get_parameters(),
+            return_schema=self.get_return_schema(),
+            permission_class=self.permission_class,
+            side_effect_scope=self.side_effect_scope,
+            requires_confirmation=self.requires_confirmation,
+            is_streaming=self.is_streaming,
+            tags=self.tags,
+        )
+
+    @abstractmethod
+    def get_parameters(self) -> dict[str, Any]:
+        """获取参数 Schema（JSON Schema 格式）
+
+        Returns:
+            参数 schema
+        """
+        pass
+
+    @abstractmethod
+    def get_return_schema(self) -> dict[str, Any]:
+        """获取返回值 Schema
+
+        Returns:
+            返回值 schema
+        """
+        pass
+
+    @abstractmethod
+    async def execute(self, **kwargs) -> T:
+        """执行工具
+
+        Args:
+            **kwargs: 工具参数
+
+        Returns:
+            执行结果
+        """
+        pass
+
+    async def execute_safe(self, **kwargs) -> dict[str, Any]:
+        """安全执行工具，捕获异常
+
+        Args:
+            **kwargs: 工具参数
+
+        Returns:
+            包含 success 和 result/error 的字典
+        """
+        try:
+            result = await self.execute(**kwargs)
+            return {"success": True, "result": result}
+        except Exception as e:
+            return {"success": False, "error": str(e)}
+
+    def __repr__(self) -> str:
+        return f"<{self.__class__.__name__}(name={self.name!r})>"
+
+
+class ReadTool(BaseTool):
+    """只读工具基类"""
+
+    def __init__(self, **kwargs):
+        kwargs.setdefault("category", ToolCategory.READ)
+        kwargs.setdefault("permission_class", PermissionClass.READ)
+        kwargs.setdefault("side_effect_scope", SideEffectScope.NONE)
+        super().__init__(**kwargs)
+
+
+class WriteTool(BaseTool):
+    """写入工具基类"""
+
+    def __init__(self, **kwargs):
+        kwargs.setdefault("category", ToolCategory.WRITE)
+        kwargs.setdefault("permission_class", PermissionClass.WRITE)
+        kwargs.setdefault("side_effect_scope", SideEffectScope.LOCAL_STATE)
+        super().__init__(**kwargs)
+
+
+class DBWriteTool(BaseTool):
+    """数据库写入工具基类"""
+
+    def __init__(self, **kwargs):
+        kwargs.setdefault("category", ToolCategory.DB_WRITE)
+        kwargs.setdefault("permission_class", PermissionClass.WRITE)
+        kwargs.setdefault("side_effect_scope", SideEffectScope.DB_WRITE)
+        kwargs.setdefault("requires_confirmation", True)
+        super().__init__(**kwargs)
+
+
+class ExternalTool(BaseTool):
+    """外部工具基类（执行外部命令等）"""
+
+    def __init__(self, **kwargs):
+        kwargs.setdefault("category", ToolCategory.EXTERNAL)
+        kwargs.setdefault("permission_class", PermissionClass.EXTERNAL)
+        kwargs.setdefault("side_effect_scope", SideEffectScope.NETWORK)
+        kwargs.setdefault("requires_confirmation", True)
+        super().__init__(**kwargs)
+
+
+class NetworkTool(BaseTool):
+    """网络工具基类"""
+
+    def __init__(self, **kwargs):
+        kwargs.setdefault("category", ToolCategory.NETWORK)
+        kwargs.setdefault("permission_class", PermissionClass.EXTERNAL)
+        kwargs.setdefault("side_effect_scope", SideEffectScope.NETWORK)
+        super().__init__(**kwargs)