get_desktop_path() does not return correct Desktop path

Description:
The function responsible for retrieving the Desktop path doesn't return the expected location on most systems, especially across different operating systems. As a result, any file or folder creation fails silently or ends up in the wrong location.

_Hint: Check if the function dynamically resolves the user’s actual home directory and appends 'Desktop'._

Find the get_desktop_path() function in the codebase. Examine how it constructs the path, likely using os.path.join. Research platform-specific ways to get the user's home directory (e.g., os.path.expanduser('~') or pathlib.Path.home()) and the correct Desktop folder name (e.g., 'Desktop' on macOS/Linux, 'Desktop' on Windows). Write a test to verify the function returns the correct path on your system.

索引モデルが issue の本文から書いたものです。