We used to have a "front_end_edit" plugin but it was removed years ago because of severe security issues.
We kept it in our "Unsupported" repository for legacy reasons but it doesn't work anymore.(href="https://github.com/zenphoto/Unsupported/tree/master/plugins/front_end_edit)
There are no plans to revive it but we always welcome 3rd party solutions.
A possible route, right now, could be to use the admin toolbox (visible on the front-end when logged in) and click "Edit image" when you are on an image page.
That will however bring you to the back-end edit page.
There's also the "Bulk actions" dropdown (on the back-end) to add tags to items.
For the future, the easiest would be to include the information in the image EXIF data. Zenphoto will extract that automatically.