ultrahdr_app throws an error when trying to write a path with Chinese characters

[gregbenz]

It appears the CLI tool cannot handle some valid characters in paths, such as the Chinese character below.

Using the command line flag:
-z \"C:\Users\admin\Documents\張\out.jpg"

Will show an error message:
unable to write to file: C:\Users\admin\Documents?\out.jpg

This fails under Windows 11, but seems to work OK under MacOS.

Note that other less common characters in EU languages will work in the CLI app (if they exist on the disk) - but if the path fails for other reasons, the error message will be mangled. For example, "À" shows as "└" in the path listed in the error. So the error message itself does not correctly list the path in some cases where the character itself is supported.

[kmilos]

Perhaps forcing the UTF-8 codepage on modern Windows 10 1903 or later is sufficient for this... Something along the lines of libjxl/libjxl@7b70ef1