[SYS-030] /ultrareview consumes session credit on failed launch — charged for zero-output failure

Summary

Running /ultrareview on a repo where the Claude GitHub App is not installed fails silently with:

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

The attempt is still counted against the monthly usage cap (3 sessions/month). When the user installs the GitHub App and retries, the counter shows session 2 of 3 — one credit was burned for a complete failure with zero output.

Reproduction

1. Have a private GitHub repo with Claude GitHub App NOT installed
2. Run /ultrareview <PR> — fails with 'failed to launch the remote session'
3. Install Claude GitHub App on the repo
4. Run /ultrareview <PR> again — succeeds, but counter shows '2 of 3' not '1 of 3'

Impact

• Credits should only be consumed on successful launch + output, not on failures
• The error message 'Check that this is a GitHub repo' gives zero indication that the fix is installing a GitHub App — first-time users will always burn their first session hitting this wall
• With only 3 free sessions/month this is a meaningful billing fairness issue

Two bugs in one

1. Credits consumed on failure (primary)
2. Error message doesn't tell you what to actually fix — 'Check that this is a GitHub repo' is misleading when the real issue is 'Install the Claude GitHub App'

Expected behavior

Failed launches should not consume credits. On the specific 'GitHub App not installed' error, the message should say: 'Install the Claude GitHub App on your repo at github.com/apps/claude — then retry.'

Environment

• Claude Code v2.1.111
• Private GitHub repo (ThatDragonOverThere/trading_system)
• First-time ultrareview user