37919cfe17
Layered bevy_ui treatment (sheen gradient, specular BorderGradient rim, BoxShadow) approximating frosted glass without shaders or backdrop sampling - WebGL2-safe by construction. Layout callers depend only on glass_surface() + GLASS_BORDER_PX so the material can be swapped later. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>