shadertoy-to-flutter

Convert Shadertoy GLSL fragment shaders into Flutter-compatible GLSL fragment shaders (.frag files) for use with Flutter's FragmentProgram / FragmentShader API, Impeller, or the material_palette "fill shader" / "wrap shader" pattern. Use whenever the user pastes a Shadertoy shader (or points to one on shadertoy.com) and wants to run it in Flutter, asks to port or adapt a fragment shader to Flutter, mentions making Shadertoy-style uniforms (iResolution, iTime, iMouse, iChannel*, mainImage, fragCoord) work in Flutter, or has a .frag file that won't compile in Flutter because of Shadertoy-style constructs. Also use when the user wants to build a Flutter "fill shader" or "wrap shader" starting from a shadertoy source. This is a real code transformation — entry point, uniforms, sampler calls, unsupported-feature substitution — not a simple rename.