ultraplan: cannot launch remote session despite GitHub app being installed

Reported by: Ashwin

Issue

/ultraplan fails to launch a remote session with the error:

ultraplan: cannot launch remote session —
The Claude GitHub app must be installed on this repository first.
https://github.com/apps/claude/installations/new

This error persists even after the Claude GitHub app has been correctly installed on the repository.

Steps taken

1. Initialized a git repository locally
2. Added a GitHub remote (git remote add origin https://github.com/ashwinksv/commoners.git)
3. Committed and pushed files to the remote
4. Installed the Claude GitHub app on the ashwinksv/commoners repository (via https://github.com/apps/claude/installations/new, selecting only the specific repository)
5. Verified the app appears under the repository's installations settings
6. Retried /ultraplan <prompt> — same error every time

Expected behaviour

Remote session should launch and return a browser link for web editing.

Actual behaviour

Fails with "Claude GitHub app must be installed" even though it is installed.

Environment

• Platform: Windows 10
• Shell: PowerShell