Refactor: Reorganize workspaces and remove assets/ directory

Workspace structure now:
- workspaces/{main,test}/obj/      (3D models)
- workspaces/{main,test}/shaders/  (WGSL shaders)
- workspaces/{main,test}/music/    (audio samples)

Changes:
- Moved workspaces/*/assets/music/ → workspaces/*/music/
- Updated assets.txt paths (assets/music/ → music/)
- Moved test_demo.{seq,track} to tools/
- Moved assets/originals/ → tools/originals/
- Removed assets/common/ (legacy, duplicated in workspaces)
- Removed assets/final/ (legacy, superseded by workspaces)
- Updated hot-reload paths in main.cc
- Updated CMake references for test_demo and validation
- Updated gen_spectrograms.sh paths

handoff(Claude): Workspace reorganization complete

1 files changed, 0 insertions, 27 deletions

diff --git a/assets/common/shaders/compute/gen_mask.wgsl b/assets/common/shaders/compute/gen_mask.wgsl
deleted file mode 100644
index 1ce9f52..0000000
--- a/assets/common/shaders/compute/gen_mask.wgsl
+++ /dev/null
@@ -1,27 +0,0 @@
-// This file is part of the 64k demo project.
-// GPU composite shader: Multiply texture A by texture B (masking).
-
-struct MaskParams {
-  width: u32,
-  height: u32,
-}
-
-@group(0) @binding(0) var output_tex: texture_storage_2d<rgba8unorm, write>;
-@group(0) @binding(1) var<uniform> params: MaskParams;
-@group(0) @binding(2) var input_a: texture_2d<f32>;
-@group(0) @binding(3) var input_b: texture_2d<f32>;
-@group(0) @binding(4) var tex_sampler: sampler;
-
-@compute @workgroup_size(8, 8, 1)
-fn main(@builtin(global_invocation_id) id: vec3<u32>) {
-  if (id.x >= params.width || id.y >= params.height) { return; }
-
-  let uv = vec2<f32>(f32(id.x) / f32(params.width),
-                      f32(id.y) / f32(params.height));
-
-  let color_a = textureSampleLevel(input_a, tex_sampler, uv, 0.0);
-  let mask_b = textureSampleLevel(input_b, tex_sampler, uv, 0.0);
-  let masked = color_a * mask_b;
-
-  textureStore(output_tex, id.xy, masked);
-}