修改了nanobot，往Hermes agent的风格走，进度1/3

app-instance/backend/beaver/interfaces/web/schemas/chat.py

@@ -0,0 +1,93 @@
+"""Chat-related web schemas."""
+
+from __future__ import annotations
+
+from typing import Any
+
+try:
+    from pydantic import BaseModel, Field
+except ModuleNotFoundError:  # pragma: no cover - fallback for skeleton-only environments
+    class BaseModel:
+        """Very small fallback shim used only so imports work without pydantic."""
+
+        def __init__(self, **kwargs: Any) -> None:
+            annotations = getattr(self.__class__, "__annotations__", {})
+            for name in annotations:
+                default = getattr(self.__class__, name, None)
+                if name in kwargs:
+                    value = kwargs[name]
+                else:
+                    value = default
+                setattr(self, name, value)
+
+        def model_dump(self, *, exclude_none: bool = False) -> dict[str, Any]:
+            data = dict(self.__dict__)
+            if exclude_none:
+                data = {key: value for key, value in data.items() if value is not None}
+            return data
+
+    def Field(default: Any = None, **kwargs: Any) -> Any:
+        default_factory = kwargs.get("default_factory")
+        if default_factory is not None:
+            return default_factory()
+        return default
+
+
+class WebProviderTarget(BaseModel):
+    """Web-facing provider target shape.
+
+    先保持和 runtime 里的 `ProviderTarget` 接近，但只暴露 Web 当前需要的字段。
+    后面如果 provider 层扩字段，再由这里显式补齐。
+    """
+
+    provider: str | None = None
+    model: str | None = None
+    api_key: str | None = None
+    api_base: str | None = None
+    extra_headers: dict[str, str] | None = None
+
+
+class WebChatRequest(BaseModel):
+    """最小正式 chat 请求结构。"""
+
+    message: str = Field(min_length=1)
+    session_id: str | None = None
+    user_id: str | None = None
+    title: str | None = None
+    execution_context: str | None = None
+    model: str | None = None
+    provider_name: str | None = None
+    embedding_model: str | None = None
+    temperature: float | None = None
+    max_tokens: int | None = None
+    max_tool_iterations: int | None = None
+    fallback_target: WebProviderTarget | None = None
+    auxiliary_target: WebProviderTarget | None = None
+    embedding_target: WebProviderTarget | None = None
+
+
+class WebChatResponse(BaseModel):
+    """最小正式 chat 响应结构。"""
+
+    session_id: str
+    run_id: str
+    output_text: str
+    finish_reason: str
+    tool_iterations: int
+    provider_name: str | None = None
+    model: str | None = None
+    usage: dict[str, Any] = Field(default_factory=dict)
+
+
+class WebStatusResponse(BaseModel):
+    """Web 宿主层状态响应。"""
+
+    status: str
+    running: bool
+    mode: str
+
+
+class WebErrorResponse(BaseModel):
+    """统一错误响应结构。"""
+
+    detail: str