Fixed
CustomShaderEffect() now accepts glslFragmentShader parameter: The helper function was missing the GLSL shader parameter, causing all effects created via CustomShaderEffect() to have no GLSL fallback. Since Sigil now uses WebGL exclusively for effects (due to Materia limitations), this meant effects couldn't render.
Usage
CustomShaderEffect(
id = "aurora",
fragmentShader = wgslShaderCode, // WGSL (for future WebGPU support)
glslFragmentShader = glslShaderCode, // GLSL (required for current WebGL rendering)
uniforms = mapOf(...)
)