GLSL-PathTracer Port for Shadertoy

Load a scene (BVH, vertices, normals, materials, lights, ...) into ShaderToy. The scene was built by a port of GLSL-PathTracer (see https://github.com/knightcrawler25/GLSL-PathTracer) in typeScript, and stored in the cloud. Functionalities: * Monkey-patches core methods on ShaderToy, Effect, EffectPass, and renderer methods (AttachTextures, AttachShader, DrawFullScreenTriangle_XY) to alter default rendering flow. * Replaces single full-frame rendering with tile-based progressive rendering (4x4 tiles), sample accumulation, ping-pong buffers, and per-tile viewport control. * Adds custom buffer semantics for Buffer B/C/D/Image to support path-trace pass, accumulation pass, output pass, and final display logic. * Adds support for a custom floats input type (binary float data) so mesh/scene data can be uploaded as GPU textures. * Optionally adds a denoiser pipeline (readback → denoise → upload result texture), with periodic execution and async backend readiness. * Extends the Shadertoy UI by creating an iChannel4 envmap slot dynamically (including sampler controls) when needed.