The titan-iac-quality-gate multibranch job's git branch source was
defined without a discovery trait, so JCasC created it with empty
traits and it indexed zero branches — no PR ever built, no status
check was ever reported, and auto-merge could never fire. Add
traits { gitBranchDiscovery() } to match every working multibranch
job (e.g. hermes-code-demo-branches).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>