feat: 实现 AgentScope ReAct Runner 两阶段执行并重构事件处理

backend/src/v1/agent/router.py

@@ -37,6 +37,7 @@ from v1.agent.schemas import (
     AttachmentReference,
     AttachmentSignedUrlResponse,
     AttachmentUploadResponse,
+    HistorySnapshotResponse,
     TaskAcceptedResponse,
 )
 from v1.agent.service import AgentService, asr_service
@@ -219,13 +220,13 @@ async def stream_events(
     )
 
 
-@router.get("/history")
+@router.get("/history", response_model=HistorySnapshotResponse)
 async def get_user_history_snapshot(
     service: Annotated[AgentService, Depends(get_agent_service)],
     current_user: Annotated[CurrentUser, Depends(get_current_user)],
     thread_id: str | None = Query(default=None, alias="threadId"),
     before: date | None = Query(default=None),
-) -> dict[str, object]:
+) -> HistorySnapshotResponse:
     return await service.get_user_history_snapshot(
         current_user=current_user,
         thread_id=thread_id,