CreatePlate copied a rail-backed stock's zones but not its rail, so the
materialized plate fell back to the bottom edge spacing as its clamp
clearance while every engine packed to the rail's own. With a rail
clearance below the edge spacing, valid layouts from all engines were
rejected as clamp violations. Carry the rail and any removed clamps
across, sharing the rule the commit path already used.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>