Fix FastAPI response annotation for /output route

hf_app.py

@@ -6,7 +6,7 @@ import os
 import shutil
 
 import torch
-from fastapi import FastAPI, File, Form, Request, UploadFile
+from fastapi import FastAPI, File, Form, Request, Response, UploadFile
 from fastapi.responses import FileResponse, HTMLResponse, JSONResponse
 from fastapi.staticfiles import StaticFiles
 from fastapi.templating import Jinja2Templates
@@ -292,8 +292,8 @@ async def pdf_details(pdf_stem: str) -> JSONResponse:
     )
 
 
-@app.get("/output/{filename:path}")
-async def output_file(filename: str) -> FileResponse | JSONResponse:
+@app.get("/output/{filename:path}", response_model=None)
+async def output_file(filename: str):
     """Serve output files (PDFs, images, markdown)."""
 
     output_root = OUTPUT_FOLDER.resolve()