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/worker/agent_run_worker.py

@@ -0,0 +1,45 @@
+from collections.abc import Awaitable, Callable
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.errors import AgentError, RecoverableAgentError
+from app.repository.agent_run_repository import AgentRunRepository
+
+
+class AgentRunWorker:
+    def __init__(
+        self,
+        session: AsyncSession,
+        execute_run: Callable[[str], Awaitable[None]],
+        worker_id: str,
+        lease_seconds: int = 60,
+        retry_limit: int = 3,
+    ) -> None:
+        self.repository = AgentRunRepository(session)
+        self.execute_run = execute_run
+        self.worker_id = worker_id
+        self.lease_seconds = lease_seconds
+        self.retry_limit = retry_limit
+
+    async def claim_and_execute(self, run_id: str) -> bool:
+        async with self.repository.session.begin():
+            claimed = await self.repository.claim(run_id, self.worker_id, self.lease_seconds)
+        if not claimed:
+            return False
+        try:
+            await self.execute_run(run_id)
+        except RecoverableAgentError as exc:
+            async with self.repository.session.begin():
+                await self.repository.record_failure(run_id, exc.code, self.retry_limit)
+            return False
+        except AgentError as exc:
+            async with self.repository.session.begin():
+                await self.repository.record_failure(run_id, exc.code, 0)
+            return False
+        return True
+
+    async def renew(self, run_id: str) -> bool:
+        return await self.repository.renew(run_id, self.worker_id, self.lease_seconds)
+
+    async def cancellation_requested(self, run_id: str) -> bool:
+        return await self.repository.is_cancel_requested(run_id)