WebGL on the GPU: shaders run on the real device

WebGL had always run on the CPU - a from-scratch software rasteriser walking every pixel through a GLSL interpreter. Now the common shader shape runs on the actual GPU: the page's GLSL is translated to WGSL, its vertex buffers and uniforms are uploaded, and wgpu draws the triangles on the device. A real WebGL frame - position and colour attributes, colour varyings, and mat4/vec4 uniforms, drawArrays and drawElements - now renders on the GPU and matches the software pipeline within a single level per channel (interiors identical, only anti-aliased triangle edges differ). The translation is an accelerator, never a correctness risk: any shader it cannot yet translate (textures, user functions, loops) falls back to the proven software path, so nothing renders wrong. The GPU aspect moves 47 to 48. Textures and control-flow shaders on the GPU are the next slice. The overall holds at 57.