fix(tools/shadertoy): fix Next Steps instructions and update EFFECT_WORKFLOW.md

- Fix assets.txt path: shaders/xxx.wgsl (not ../../src/shaders/)
- Fix shader output path to workspaces/main/shaders/
- Step 5: reference cmake/DemoSourceLists.cmake COMMON_GPU_EFFECTS (not CMakeLists.txt GPU_SOURCES)
- Add step for test_demo_effects.cc

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/src/effects/scene2_effect.h b/src/effects/scene2_effect.h
new file mode 100644
index 0000000..effc19f
--- /dev/null
+++ b/src/effects/scene2_effect.h
@@ -0,0 +1,24 @@
+// This file is part of the 64k demo project.
+// Scene2 effect - ShaderToy conversion (scene)
+// Generated by convert_shadertoy.py
+
+#pragma once
+
+#include "gpu/effect.h"
+#include "gpu/wgpu_resource.h"
+
+class Scene2Effect : public Effect {
+ public:
+  Scene2Effect(const GpuContext& ctx,
+               const std::vector<std::string>& inputs,
+               const std::vector<std::string>& outputs,
+               float start_time, float end_time);
+
+  void render(WGPUCommandEncoder encoder,
+              const UniformsSequenceParams& params,
+              NodeRegistry& nodes) override;
+
+ private:
+  RenderPipeline pipeline_;
+  BindGroup bind_group_;
+};