The gate blocked approved clean-room squashes on per-file shrinkage with no
override path ("AI merge diff-volume gate blocked the approved squash").
Removed by operator decision: delete checkDiffVolume/DiffVolumeRegressionError,
the merge:diff-volume-blocked audit event, the runDiffVolumeGate call sites in
every legacy squash finalizer, the AI-merge pre-land check, and the
mergeDiffVolume* settings. File scope remains the pre-land guard; the
post-squash audit policy remains the shrinkage backstop.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
