First of three M3 cycles (Theme -> shell 2a -> Title). Palette.gd consts
as the single source of truth; game_theme.tres for flat-bordered UI;
shaders for the three signature surfaces. EB Garamond replaces
proprietary Georgia. Proof is a human-eyeballed showcase harness.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
