初始化仅前端版本

backend/main.py

@@ -0,0 +1,12 @@
+# backend/app/main.py
+from fastapi import FastAPI
+from .api.routes import router
+
+app = FastAPI(title="LLM Workflow Engine")
+
+# 注册路由
+app.include_router(router, prefix="/api")
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run(app, host="0.0.0.0", port=8000)