When launching from an image built from a private repository, the returned error should be 403 - forbidden when the user should not access the image. <img width="852" height="764" alt="Image" src="https://github.com/user-attachments/assets/e2f864b0-66d3-4962-a440-629d336855f6" /> cc @sgaist > Change to forbidden error (403). _Originally posted by @leafty in [#1250](https://github.com/SwissDataScienceCenter/renku-data-services/pull/1250/changes#r3135756417)_
When launching from an image built from a private repository, the returned error should be 403 - forbidden when the user should not access the image.
cc @sgaist
Originally posted by @leafty in #1250