Move-to-cloud fails with generic 'remote rejected the push from the app (auth)' even though branch is confirmed already pushed and matches origin

Summary

"Move to cloud" (continuing a session in the cloud) fails every time with a generic auth error, even though the underlying git repo/push state is confirmed correct.

Steps to reproduce

1. Local repo pouyagheini-max/volt-crm (private), created and pushed via gh repo create --push from the desktop app's own machine.
2. GitHub App "Claude" installed with "All repositories" access (confirmed at github.com/settings/installations).
3. Created a Cloud Environment in the Code tab composer, selected repo volt-crm, branch main.
4. Tried "move to cloud" / continue-in-cloud 3 separate times.

Result

Every attempt fails with:

The remote rejected the push from the app (auth). Push the branch yourself from a terminal to see why, then call again — a branch that is already pushed needs no push permission from the app. Nothing was moved; this session is unchanged.

What I verified manually (all fine)

$ git status
On branch main
Your branch is up to date with 'origin/main'.
nothing to commit, working tree clean

$ git push        # using gh's own credential helper
Everything up-to-date

# local HEAD sha == remote HEAD sha (checked via `gh api repos/.../git/refs/heads/main`)

So the branch is genuinely already pushed and matches origin exactly. The failure is specifically in the app's own push-on-behalf-of-user step for the cloud-move action, not anything on the user's end.

Environment

• Claude desktop app (macOS, Apple Silicon)
• Repo: private, GitHub App installed with "All repositories" scope
• Retried 3 times over ~10 minutes, identical error each time

Happy to provide more detail/logs if useful.