After each PR merge, cascade.py scans the diff for changed claim files,
then checks all agent beliefs and positions for depends_on references.
Affected agents get inbox notifications via agent-state. Non-fatal —
cascade failure never blocks merges.
Hook point: merge.py after _embed_merged_claims, before _delete_remote_branch.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
