feat(merge): default PR merges to --no-ff merge commits; add fast-forward-only strategyVerified

Anthony Green2026-06-26 23:22:22 -0400 bbaf2ff158bb196cdedf2fad312e449a5dd4e54f
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>