feat: add persistent chat agent and indexed batch workflows

backend/wisegrade/main.py

@@ -5,6 +5,7 @@ from fastapi import FastAPI, Request
 from fastapi.responses import JSONResponse
 
 from .api import router
+from .chat_api import router as chat_router
 from .db import SessionLocal
 from .seed import seed_initial
 
@@ -19,6 +20,7 @@ async def lifespan(_app: FastAPI):
 
 app = FastAPI(title="WiseGrade 智评", version="0.1.0", lifespan=lifespan)
 app.include_router(router)
+app.include_router(chat_router)
 
 
 @app.exception_handler(ValueError)