feat: 新增 core/agents 模块和 nanobot

- 新增 agents 模块，包含 agent、api、skills 等子模块
- 新增 nanobot 项目，支持多渠道集成
- 添加启动脚本 start-all.bat 和 start-all.sh

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

core/agents/tools/__init__.py

@@ -0,0 +1,51 @@
+"""Tools module for X-Agents.
+
+This module provides tool infrastructure for the agent system.
+It wraps and extends the nanobot tool implementation.
+"""
+
+from nanobot.agent.tools.base import Tool
+from nanobot.agent.tools.registry import ToolRegistry
+
+from agents.tools.builtin import (
+    get_builtin_tools,
+    ReadFileTool,
+    WriteFileTool,
+    ListDirectoryTool,
+    SearchTool,
+    WebSearchTool,
+    CalculatorTool,
+    GetTimeTool,
+    BashTool,
+)
+from agents.tools.manager import ToolManager
+
+
+def create_default_registry() -> ToolRegistry:
+    """Create a tool registry with default tools.
+
+    Returns:
+        Tool registry with built-in tools
+    """
+    registry = ToolRegistry()
+    # Register built-in tools
+    for tool in get_builtin_tools():
+        registry.register(tool)
+    return registry
+
+
+__all__ = [
+    "Tool",
+    "ToolRegistry",
+    "ToolManager",
+    "create_default_registry",
+    "get_builtin_tools",
+    "ReadFileTool",
+    "WriteFileTool",
+    "ListDirectoryTool",
+    "SearchTool",
+    "WebSearchTool",
+    "CalculatorTool",
+    "GetTimeTool",
+    "BashTool",
+]