Add voiceovers to video projects

The Video Editor now has voiceover support, making it easier to turn generated visuals, product clips, and campaign ideas into finished social assets. It is part of a larger push to make video work in Youanai feel like one flow: make the asset, edit the asset, add context, and ship. We also moved Veo video generation onto the current Veo 3.1 model, with Sora options still available when they fit the job better.

We're still formatting this release note for the site. Check back soon for the full write-up.