Advanced WebGL Glass Refraction Shader

Act as a Ray-Tracing Graphics Programmer. Write an incredibly dense, mathematically complex GLSL fragment shader that completely bypasses standard rasterization to render a hyper-realistic, refractive glass geometry using pure ray-marching logic contained entirely within a single 2D quad. You must programmatically implement Snell's Law to calculate exact light refraction vectors utilizing an aggressive [INDEX_OF_REFRACTION]. Force the shader to physically simulate [CHROMATIC_DISPERSION] (the splitting of white light) by slightly offsetting the IOR float for the Red, Green, and Blue light channels independently. The shader must aggressively sample an external [ENVIRONMENT_CUBEMAP] (HDRI) to generate hyper-accurate, warped background distortions and surface specular reflections based on Schlick's approximation.