[BUG] /ultrareview fails with "failed to launch the remote session" under WSL2, same setup works from Windows-native CLI

Summary

/ultrareview <PR#> consistently fails in Claude Code running inside WSL2 with the generic error:

Ultrareview failed to launch the remote session. Check that this is a GitHub repo and try again.

The identical command, on the identical account, with an identical repo and PR, succeeds immediately when invoked from the Windows-native Claude Code CLI. The WSL-vs-Windows CLI is the only changed variable.

Environment (failing)

• OS: Ubuntu 24.04.4 LTS inside WSL2 (Linux 5.15.167.4-microsoft-standard-WSL2 on Windows host)
• Claude Code: 2.1.114
• gh: 2.45.0
• git: 2.43.0
• Plan: Max (claude.ai authed, not API-key)
• Auth path: /web-setup (gh token sync), completed successfully (Connected as <user>)

Environment (working — same account, same repo)

• OS: Windows 11, PowerShell
• Claude Code: same 2.1.114

Reproduction (minimal)

1. In WSL Claude Code, with a public GitHub repo + an open non-draft PR from a feature branch to main:
2. Run /ultrareview <PR#>
3. Confirmation dialog appears showing "Free ultrareview 1 of 3" and correct PR metadata
4. Press Enter to confirm
5. Immediately errors with Ultrareview failed to launch the remote session. Check that this is a GitHub repo and try again.

Redo identical steps from Windows-native Claude Code CLI on the same account: launches successfully on first attempt.

What I've ruled out

• Repo visibility / private vs public (tested both)
• PR draft state (tested both)
• Bundle vs PR mode (PR mode hits this; bundle mode hits the separate unfixed #49458)
• /web-setup status (re-ran, reports Connected as <user>)
• gh token scopes (includes workflow)
• API overload (waited for Anthropic status to be fully green, retried — same failure)
• Default branch / merge-base / branch topology (verified on GitHub — default branch main, PR MERGEABLE, merge-base resolves cleanly locally)
• Cloud environment provisioning (visible in claude.ai/code web UI; repo and branches render correctly in the branch picker)

The message "Check that this is a GitHub repo" suggests the launch-handoff is failing at a repo-identification step that succeeds in the Windows CLI path with the identical remote URL.

Workaround

Run /ultrareview from Windows-native Claude Code CLI, not from WSL. Details and a step-by-step setup template available on request.