fix

app/main.py

@@ -37,19 +37,20 @@ def process_input(text: str):
 def upload(files: list[UploadFile]):
     session_assistant.clear()
     session_messages = []
+    files_dir = os.path.expanduser("~/wtp_be_files/")
     
     try:
-        os.makedirs("~/wtp_be_files/")
+        os.makedirs(files_dir)
         for file in files:
             try:
                 file.file.seek(0)
-                with Path("~/wtp_be_files/").open("wb") as destination:
+                with Path(files_dir).open("wb") as destination:
                     shutil.copyfileobj(file.file, destination)
             finally:
                 file.file.close()
     finally:
-        session_assistant.ingest("~/wtp_be_files/")
-        shutil.rmtree("~/wtp_be_files/")
+        session_assistant.ingest(files_dir)
+        shutil.rmtree(files_dir)
 
     return "Files inserted!"