Fix file object has no attribute read

app.py

@@ -92,7 +92,9 @@ def call_generate(file_obj, topics, n_questions, difficulty, question_type):
         return {"error": "No file uploaded."}
 
     # Read the uploaded file bytes and create multipart payload
-    file_bytes = file_obj.read()
+    file_bytes = read_file_input(file_obj)
+    if not file_bytes:
+        return {"error": "Could not read uploaded file (empty or unknown format)."}
     files = {"file": ("uploaded_file", file_bytes, "application/octet-stream")}
 
     data = {