feat：优化流式输出，增加临时多轮对话记录

app/main.py

@@ -7,6 +7,7 @@ from fastapi import FastAPI
 from loguru import logger
 
 from app.api.agent import router
+from app.api.conversations import router as conversation_router
 from app.core.exceptions import register_exception_handlers
 from app.core.logging import setup_logging
 
@@ -19,7 +20,12 @@ async def lifespan(application: FastAPI):
     from app.processor.graph import build_graph
     from app.services.agent import AgentService
 
-    application.state.agent_service = AgentService(build_graph())
+    from app.services.conversation import InMemoryConversationStore
+
+    # TODO 接入 MongoDB 后替换为持久化实现，并同步替换图的 checkpointer
+    store = InMemoryConversationStore()
+    application.state.conversation_store = store
+    application.state.agent_service = AgentService(build_graph(), store)
     try:
         yield
     finally:
@@ -38,6 +44,7 @@ def create_app() -> FastAPI:
     # 统一处理请求校验、HTTP 错误和未捕获异常
     register_exception_handlers(application)
     application.include_router(router)
+    application.include_router(conversation_router)
     return application