修改了nanobot，往Hermes agent的风格走，进度1/3

app-instance/backend/beaver/interfaces/web/deps.py

@@ -0,0 +1,27 @@
+"""Web dependency wiring."""
+
+from __future__ import annotations
+
+from typing import Any
+
+from beaver.services.agent_service import AgentService
+
+try:
+    from fastapi import HTTPException
+except ModuleNotFoundError:  # pragma: no cover - fallback for skeleton-only environments
+    class HTTPException(Exception):
+        """Minimal fallback exception matching FastAPI's constructor shape."""
+
+        def __init__(self, status_code: int, detail: str) -> None:
+            super().__init__(detail)
+            self.status_code = status_code
+            self.detail = detail
+
+
+def get_agent_service(request: Any) -> AgentService:
+    """从 app state 里取当前宿主层托管的 AgentService。"""
+
+    service = getattr(request.app.state, "agent_service", None)
+    if not isinstance(service, AgentService):
+        raise HTTPException(status_code=503, detail="AgentService is not ready")
+    return service