修改了nanobot，往Hermes agent的风格走，进度1/3

app-instance/backend/beaver/tools/__init__.py

@@ -0,0 +1,15 @@
+"""Tool system for Beaver."""
+
+from .base import BaseTool, ObjectBackedTool, ToolContext, ToolResult, ToolSpec
+from .registry import ToolRegistry
+from .runtime import ToolExecutor
+
+__all__ = [
+    "BaseTool",
+    "ObjectBackedTool",
+    "ToolContext",
+    "ToolExecutor",
+    "ToolRegistry",
+    "ToolResult",
+    "ToolSpec",
+]