I wonder, why images have to be uploaded to the commons. Most
wikipedians upload their immages to their 'local' wp. One major reason
is the language, other reasons are national rigths etc.
If i had to make a catalog of all files and images used in WPs
worldwide, i would directly use all wp-databases existing. I would scan
their database an just implement a link to the images to make them
visible. No uploads of images - Just Links.
Further i would also implement some kind of multilanguage-feature.
Images are not 'common', when you have to learn a language before. So i
would import the image discription where the image comes from and update
it. Aditionally descriptions in other languages should be possible
justai