p004 (tagged mate) let the defender take the rook; the black rook is gone
so Ra8 is mate. p009 was tagged promotion with a rook move; it is a back-
rank mate. p019 (tagged mate) left the queen hanging; it is now Qh8 mate
with the king guarding. Rows before the change are in this file; all three
answers were checked as mate with chess.js.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>