- Implement 16x16 procedural textures using Perlin noise (RCT-style)
- Each tile has unique texture based on grid position and biome
- GL_NEAREST filtering for retro pixelated look
- Random seeds for both heightmap and textures on regeneration (R key)
- Disable lighting on top faces to show pure texture colors
- Uniform brown color for side faces with shading
- Update documentation (README, docs/) with texture features
- Update copilot instructions with communication rules
