Constructor maak-positie returns dispatch closure with rij/kolom getters,
rij!/kolom! mutators, vergelijk? predicate, and beweeg method.
All coordinates are in grid units, not pixels.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
All hardcoded values (cell sizes, offsets, sprite scales, timing, score,
UI positions, cell type codes) are now named constants in an R7RS library.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>