Replaces the rotated 2x2 CSS grid diamond with an SVG baseball diamond
containing 4 small diamond-shaped bases at 1B/2B/3B/Home positions.
Fill order: east(1B) → north(2B) → west(3B) → south(Home).
Keeps all existing controls and tier preset properties intact.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
