修改了nanobot，往Hermes agent的风格走，进度1/3

app-instance/backend/beaver/engine/loader.py

@@ -0,0 +1,154 @@
+"""Centralized runtime loading for Beaver agents."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from pathlib import Path
+from typing import Callable
+
+from beaver.engine.context import ContextBuilder
+from beaver.engine.session import SessionManager
+from beaver.memory.curated.store import MemoryStore
+from beaver.services.memory_service import MemoryService
+from beaver.skills import SkillAssembler, SkillsLoader
+from beaver.tools import ObjectBackedTool, ToolExecutor, ToolRegistry
+from beaver.tools.builtins import EchoTool, MemoryTool, SessionSearchTool, SkillViewTool
+
+
+@dataclass(slots=True)
+class EngineLoadResult:
+    """描述当前 agent runtime 已经装好的依赖。
+
+    这里同时保留两类字段：
+    1. `tools/skills/memory_stores/permissions`
+       - 便于做状态展示、调试、轻量测试
+    2. `session_manager/tool_registry/...`
+       - 供真正的运行时主链直接使用
+    """
+
+    workspace: Path
+    tools: list[str] = field(default_factory=list)
+    skills: list[str] = field(default_factory=list)
+    memory_stores: list[str] = field(default_factory=list)
+    permissions: list[str] = field(default_factory=list)
+    session_manager: SessionManager | None = None
+    curated_memory_store: MemoryStore | None = None
+    memory_service: MemoryService | None = None
+    tool_registry: ToolRegistry | None = None
+    tool_executor: ToolExecutor | None = None
+    context_builder: ContextBuilder | None = None
+    skills_loader: SkillsLoader | None = None
+    skill_assembler: SkillAssembler | None = None
+    closeables: list[tuple[str, Callable[[], None]]] = field(default_factory=list, repr=False)
+    closed: bool = False
+
+    def register_closeable(self, name: str, close_fn: Callable[[], None]) -> None:
+        """登记一个由 runtime 统一关闭的资源。"""
+
+        self.closeables.append((name, close_fn))
+
+    def close(self) -> None:
+        """按后进先出顺序关闭 runtime 资源。
+
+        这一步先保持同步、最小、可组合：
+        1. 只管理已经明确需要关闭的资源
+        2. 暂不引入 async shutdown 协议
+        3. 为后续 Web/Gateway lifespan 留统一入口
+        """
+
+        if self.closed:
+            return
+
+        errors: list[tuple[str, BaseException]] = []
+        for name, close_fn in reversed(self.closeables):
+            try:
+                close_fn()
+            except BaseException as exc:  # pragma: no cover - defensive cleanup path
+                errors.append((name, exc))
+        self.closed = True
+
+        if errors:
+            parts = ", ".join(f"{name}: {exc}" for name, exc in errors)
+            raise RuntimeError(f"Runtime shutdown failed for {parts}")
+
+
+class EngineLoader:
+    """为任意 Beaver agent 装载共享 runtime 能力。
+
+    当前先做“最小可运行主链”需要的装配：
+    - session manager
+    - curated memory store
+    - context builder
+    - built-in tools
+    - tool executor
+
+    等主链跑稳后，再把 skills、权限、MCP、delegation 逐步加进来。
+    """
+
+    def __init__(
+        self,
+        *,
+        workspace: str | Path | None = None,
+        session_manager: SessionManager | None = None,
+        curated_memory_store: MemoryStore | None = None,
+        memory_service: MemoryService | None = None,
+        tool_registry: ToolRegistry | None = None,
+        context_builder: ContextBuilder | None = None,
+        skills_loader: SkillsLoader | None = None,
+        skill_assembler: SkillAssembler | None = None,
+    ) -> None:
+        self.workspace = Path(workspace or Path.cwd())
+        self._session_manager = session_manager
+        self._curated_memory_store = curated_memory_store
+        self._memory_service = memory_service
+        self._tool_registry = tool_registry
+        self._context_builder = context_builder
+        self._skills_loader = skills_loader
+        self._skill_assembler = skill_assembler
+
+    def load(self) -> EngineLoadResult:
+        """装配当前主链需要的最小 runtime 对象。"""
+
+        workspace = self.workspace
+        session_manager = self._session_manager or SessionManager(workspace)
+
+        curated_root = workspace / "memory" / "curated"
+        curated_memory_store = self._curated_memory_store or MemoryStore(curated_root)
+        memory_service = self._memory_service or MemoryService(curated_root, store=curated_memory_store)
+        memory_service.initialize()
+
+        tool_registry = self._tool_registry or ToolRegistry()
+        skills_loader = self._skills_loader or SkillsLoader(workspace)
+        if self._tool_registry is None:
+            # 这里先注册最小工具集，满足主链的 tool loop。
+            tool_registry.register_many(
+                [
+                    ObjectBackedTool(EchoTool()),
+                    ObjectBackedTool(MemoryTool(store=memory_service.get_store())),
+                    ObjectBackedTool(SkillViewTool(loader=skills_loader)),
+                    ObjectBackedTool(SessionSearchTool(db=session_manager)),
+                ]
+            )
+
+        context_builder = self._context_builder or ContextBuilder()
+        tool_executor = ToolExecutor(tool_registry)
+        skill_assembler = self._skill_assembler or SkillAssembler(skills_loader)
+
+        result = EngineLoadResult(
+            workspace=workspace,
+            tools=[spec.name for spec in tool_registry.list_specs()],
+            skills=[record.name for record in skills_loader.list_skills(filter_unavailable=False)],
+            memory_stores=["curated"],
+            permissions=[],
+            session_manager=session_manager,
+            curated_memory_store=memory_service.get_store(),
+            memory_service=memory_service,
+            tool_registry=tool_registry,
+            tool_executor=tool_executor,
+            context_builder=context_builder,
+            skills_loader=skills_loader,
+            skill_assembler=skill_assembler,
+        )
+        if self._session_manager is None:
+            result.register_closeable("session_manager", session_manager.close)
+        return result