Change 33482
Add the 'Merge Down, Copy Up' mantra as an explicit callout before Step 9: always Merge Down before a Copy Up, in either direction, anywhere in this process.
Prompted by two real regressions found 2026-09-04 (ReleaseNotes.adoc content gap, README.md link-rendering regression) that both traced back to a Copy Up done without a preceding Merge Down, silently overwriting a downstream-only fix with stale upstream content.
Agent: Claude Sonnet 5 (claude-sonnet-5), via Claude Code.
Prompted by two real regressions found 2026-09-04 (ReleaseNotes.adoc content gap, README.md link-rendering regression) that both traced back to a Copy Up done without a preceding Merge Down, silently overwriting a downstream-only fix with stale upstream content.
Agent: Claude Sonnet 5 (claude-sonnet-5), via Claude Code.