docs: 品牌全量口径统一为「南方基金」+ 作废文档清理

1) 客服 Agent 四份交付文档 + 构建脚手架：品牌由包装占位 XX科技 / 旧名 南方财富
   统一为南方基金（热线 400-889-8899 / 官网 nffund.com），系统名改为「智能服务系统」；
   同步追加 §0.4 修订记录行，工程记录行保留原占位字面以支撑硬编码扫描验收。
2) 开发文档：清理 28 份已作废/残留文档（14 份移出归档 + 14 份仓库副本），
   新增《文档规整方案与开发前待决事项-2026-09-17》。
3) 客服agent 四份交付文档首次纳入本分支。

app/service/risk_agent_model_client.py

@@ -0,0 +1,112 @@
+"""风控 Agent 专用的模型工具调用客户端。"""
+
+from __future__ import annotations
+
+from typing import Any, Protocol
+
+import httpx
+
+from app.core.errors import (
+    DependencyUnavailableError,
+    RecoverableAgentError,
+    UpstreamTimeoutError,
+)
+from app.service.model_gateway import (
+    DatabaseModelEndpointResolver,
+    EnvironmentSecretResolver,
+)
+
+
+class RiskAgentEndpointResolver(Protocol):
+    async def resolve(self, *, agent_type: str, task_type: str) -> list[Any]: ...
+
+
+class RiskAgentSecretResolver(Protocol):
+    def resolve(self, secret_ref: str) -> str: ...
+
+
+class RiskAgentModelClient:
+    """调用 OpenAI 兼容接口，并原样返回模型消息供业务编排校验。"""
+
+    def __init__(
+        self,
+        *,
+        endpoint_resolver: RiskAgentEndpointResolver | None = None,
+        secret_resolver: RiskAgentSecretResolver | None = None,
+        client: httpx.AsyncClient | None = None,
+        max_attempts: int = 2,
+    ) -> None:
+        self.endpoint_resolver = endpoint_resolver or DatabaseModelEndpointResolver()
+        self.secret_resolver = secret_resolver or EnvironmentSecretResolver()
+        self.client = client
+        self.max_attempts = max(1, max_attempts)
+        self._owns_client = client is None
+
+    async def chat(
+        self,
+        messages: list[dict[str, Any]],
+        *,
+        tools: list[dict[str, Any]],
+    ) -> dict[str, Any]:
+        endpoints = await self.endpoint_resolver.resolve(
+            agent_type="risk",
+            task_type="risk_agent_chat",
+        )
+        if not endpoints:
+            raise RecoverableAgentError("没有可用的风控 Agent 模型端点")
+
+        last_error: Exception | None = None
+        client = self.client or httpx.AsyncClient()
+        try:
+            for endpoint in endpoints[: self.max_attempts]:
+                try:
+                    return await self._chat_with_endpoint(client, endpoint, messages, tools)
+                except Exception as exc:
+                    last_error = exc
+            raise RecoverableAgentError("风控 Agent 模型端点调用失败") from last_error
+        finally:
+            if self._owns_client:
+                await client.aclose()
+
+    async def _chat_with_endpoint(
+        self,
+        client: httpx.AsyncClient,
+        endpoint: Any,
+        messages: list[dict[str, Any]],
+        tools: list[dict[str, Any]],
+    ) -> dict[str, Any]:
+        token = self.secret_resolver.resolve(endpoint.secret_ref)
+        url = endpoint.base_url.rstrip("/") + "/chat/completions"
+        payload: dict[str, Any] = {
+            "model": endpoint.model_name,
+            "messages": messages,
+            "temperature": 0.2,
+            "tools": tools,
+            "tool_choice": "auto",
+        }
+        try:
+            response = await client.post(
+                url,
+                headers={
+                    "Authorization": f"Bearer {token}",
+                    "Content-Type": "application/json",
+                },
+                json=payload,
+                timeout=httpx.Timeout(endpoint.timeout_ms / 1000),
+            )
+            response.raise_for_status()
+            body = response.json()
+        except httpx.TimeoutException as exc:
+            raise UpstreamTimeoutError("风控 Agent 模型调用超时") from exc
+        except httpx.HTTPError as exc:
+            raise DependencyUnavailableError("风控 Agent 模型调用失败") from exc
+        except ValueError as exc:
+            raise DependencyUnavailableError("风控 Agent 模型响应不是有效 JSON") from exc
+
+        choices = body.get("choices") if isinstance(body, dict) else None
+        if not isinstance(choices, list) or not choices:
+            raise DependencyUnavailableError("风控 Agent 模型响应缺少 choices")
+        message = choices[0].get("message") if isinstance(choices[0], dict) else None
+        if not isinstance(message, dict):
+            raise DependencyUnavailableError("风控 Agent 模型响应缺少 message")
+        return message