Create a high-quality 3D mesh model of Mercury as a textured sphere. Show realistic cratered surface texture with rough, rocky details. Use clean UV mapping and optimized textures for web (2048x2048 px). Model should be centered at origin, uniformly scaled for easy use in interactive 3D apps. Provide as a .glb or .gltf file. No extra geometry beyond the sphere. Include diffuse and normal maps if possible. Balance realism with performance.