Use the GitHub connection in v0 rather than the ZIP. It creates a repo and pushes the code, and later v0 changes land as commits (on a branch you can merge). The ZIP is a one-time copy, no way back.
Locally:
git clone <repo>
cd <repo>
npm install --legacy-peer-deps # only if the react 19 peer warnings turn into errors
npm run devPeer warnings with React 19 are common and usually harmless; only use --legacy-peer-deps when install actually fails.
Then import the repo in Vercel and add your domain there.