修改了nanobot，往Hermes agent的风格走，进度1/3

app-instance/backend/beaver/tools/builtins/skill_view.py

@@ -0,0 +1,82 @@
+"""Beaver 内置 skill_view tool。
+
+这个工具对应 Hermes 风格的显式 skill loading path：
+1. skill 正文默认不会长期塞进 system prompt
+2. 模型若想查看某个 skill 的完整正文或支持文件，必须显式调用 `skill_view`
+
+这样 skill 的按需展开路径会保持显式，而不是依赖 prompt 里长期堆目录信息。
+"""
+
+from __future__ import annotations
+
+import json
+from dataclasses import dataclass, field
+from typing import Any
+
+from beaver.skills.catalog.loader import SkillsLoader
+
+SKILL_VIEW_TOOL_DESCRIPTION = (
+    "Load the full content of a skill or one of its supporting files. "
+    "Use this when you want to inspect a skill in detail."
+)
+
+SKILL_VIEW_TOOL_PARAMETERS: dict[str, Any] = {
+    "type": "object",
+    "properties": {
+        "name": {
+            "type": "string",
+            "description": "The skill name to inspect.",
+        },
+        "file_path": {
+            "type": "string",
+            "description": (
+                "Optional relative path to a supporting file inside the skill directory, "
+                "for example 'references/usage.md'. Omit to load SKILL.md itself."
+            ),
+        },
+    },
+    "required": ["name"],
+}
+
+
+def skill_view(*, name: str, file_path: str | None = None, loader: SkillsLoader | None = None) -> str:
+    """读取 skill 正文或支持文件，并返回结构化 JSON。"""
+
+    if loader is None:
+        return json.dumps({"success": False, "error": "Skills loader is not available."}, ensure_ascii=False)
+
+    try:
+        viewed = loader.view_skill(name, file_path=file_path)
+    except FileNotFoundError as exc:
+        return json.dumps({"success": False, "error": str(exc)}, ensure_ascii=False)
+    except ValueError as exc:
+        return json.dumps({"success": False, "error": str(exc)}, ensure_ascii=False)
+
+    if viewed is None:
+        return json.dumps({"success": False, "error": f"Unknown skill '{name}'."}, ensure_ascii=False)
+
+    display_name, content = viewed
+    support_files = loader.list_skill_supporting_files(name)
+    return json.dumps(
+        {
+            "success": True,
+            "name": name,
+            "file": display_name,
+            "content": content,
+            "supporting_files": support_files,
+        },
+        ensure_ascii=False,
+    )
+
+
+@dataclass(slots=True)
+class SkillViewTool:
+    """面向 runtime 的 skill_view 工具封装。"""
+
+    loader: SkillsLoader
+    name: str = "skill_view"
+    description: str = SKILL_VIEW_TOOL_DESCRIPTION
+    parameters: dict[str, Any] = field(default_factory=lambda: dict(SKILL_VIEW_TOOL_PARAMETERS))
+
+    async def execute(self, **kwargs: Any) -> str:
+        return skill_view(loader=self.loader, **kwargs)