Merge pull request #756 from Ruijian-Zha/main

I'm considering merging this, but maybe there is a more appropriate place to make the fix. Both the gui and the terminal file selectors (I don't know which one you are using) are supposed to return List[str], and clearly they don't. Can you do the convert to string already in the selector functions and then maybe do a test on all created strings that they indeed are valid paths, along the lines of:
def is_valid_path(path: str) -> bool:
    try:
        os.stat(path)
        return True
    except OSError:
        return False

gpt_engineer/file_selector.py

@@ -292,7 +292,9 @@ def ask_for_files(metadata_db: DB, workspace_db: DB) -> None:
         sys.exit(1)
 
     if not selection_number == 3:
-        metadata_db[FILE_LIST_NAME] = "\n".join(file_path_list)
+        metadata_db[FILE_LIST_NAME] = "\n".join(
+            str(file_path) for file_path in file_path_list
+        )
 
 
 def gui_file_selector(input_path: str) -> List[str]: