refactor: move common/shaders/ to src/shaders/

Relocates shared WGSL shaders under src/ where all source code lives,
eliminating the top-level common/ directory.

- Update asset references in workspaces/main/assets.txt and workspaces/test/assets.txt
- Update docs: PROJECT_CONTEXT.md, ARCHITECTURE.md, WORKSPACE_SYSTEM.md, SHADER_REUSE_INVESTIGATION.md

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

5 files changed, 0 insertions, 150 deletions

diff --git a/common/shaders/compute/gen_blend.wgsl b/common/shaders/compute/gen_blend.wgsl
deleted file mode 100644
index c6be7bb..0000000
--- a/common/shaders/compute/gen_blend.wgsl
+++ /dev/null
@@ -1,29 +0,0 @@
-// This file is part of the 64k demo project.
-// GPU composite shader: Blend two textures.
-
-struct BlendParams {
-  width: u32,
-  height: u32,
-  blend_factor: f32,
-  _pad0: f32,
-}
-
-@group(0) @binding(0) var output_tex: texture_storage_2d<rgba8unorm, write>;
-@group(0) @binding(1) var<uniform> params: BlendParams;
-@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 = vec2f(f32(id.x) / f32(params.width),
-                 f32(id.y) / f32(params.height));
-
-  let color_a = textureSampleLevel(input_a, tex_sampler, uv, 0.0);
-  let color_b = textureSampleLevel(input_b, tex_sampler, uv, 0.0);
-  let blended = mix(color_a, color_b, params.blend_factor);
-
-  textureStore(output_tex, id.xy, blended);
-}
diff --git a/common/shaders/compute/gen_grid.wgsl b/common/shaders/compute/gen_grid.wgsl
deleted file mode 100644
index 4ce7ea3..0000000
--- a/common/shaders/compute/gen_grid.wgsl
+++ /dev/null
@@ -1,24 +0,0 @@
-// GPU procedural grid pattern generator.
-// Simple grid lines with configurable spacing and thickness.
-
-struct GridParams {
-  width: u32,
-  height: u32,
-  grid_size: u32,
-  thickness: u32,
-}
-
-@group(0) @binding(0) var output_tex: texture_storage_2d<rgba8unorm, write>;
-@group(0) @binding(1) var<uniform> params: GridParams;
-
-@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 on_line = (id.x % params.grid_size) < params.thickness ||
-                (id.y % params.grid_size) < params.thickness;
-
-  let val = select(0.0, 1.0, on_line);
-
-  textureStore(output_tex, id.xy, vec4f(val, val, val, 1.0));
-}
diff --git a/common/shaders/compute/gen_mask.wgsl b/common/shaders/compute/gen_mask.wgsl
deleted file mode 100644
index 39f5b50..0000000
--- a/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 = vec2f(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);
-}
diff --git a/common/shaders/compute/gen_noise.wgsl b/common/shaders/compute/gen_noise.wgsl
deleted file mode 100644
index 7b75f13..0000000
--- a/common/shaders/compute/gen_noise.wgsl
+++ /dev/null
@@ -1,26 +0,0 @@
-// GPU procedural noise texture generator.
-// Uses compute shader for parallel texture generation.
-
-#include "math/noise"
-
-struct NoiseParams {
-  width: u32,
-  height: u32,
-  seed: f32,
-  frequency: f32,
-}
-
-@group(0) @binding(0) var output_tex: texture_storage_2d<rgba8unorm, write>;
-@group(0) @binding(1) var<uniform> params: NoiseParams;
-
-@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 = vec2f(f32(id.x) / f32(params.width),
-                 f32(id.y) / f32(params.height));
-  let p = uv * params.frequency + params.seed;
-  let noise = noise_2d(p);
-
-  textureStore(output_tex, id.xy, vec4f(noise, noise, noise, 1.0));
-}
diff --git a/common/shaders/compute/gen_perlin.wgsl b/common/shaders/compute/gen_perlin.wgsl
deleted file mode 100644
index 2807f6d..0000000
--- a/common/shaders/compute/gen_perlin.wgsl
+++ /dev/null
@@ -1,44 +0,0 @@
-// GPU procedural Perlin noise texture generator.
-// Fractional Brownian Motion using value noise.
-
-#include "math/noise"
-
-struct PerlinParams {
-  width: u32,
-  height: u32,
-  seed: f32,
-  frequency: f32,
-  amplitude: f32,
-  amplitude_decay: f32,
-  octaves: u32,
-  _pad0: f32,  // Padding for alignment
-}
-
-@group(0) @binding(0) var output_tex: texture_storage_2d<rgba8unorm, write>;
-@group(0) @binding(1) var<uniform> params: PerlinParams;
-
-@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 = vec2f(f32(id.x) / f32(params.width),
-                 f32(id.y) / f32(params.height));
-
-  var value = 0.0;
-  var amplitude = params.amplitude;
-  var frequency = params.frequency;
-  var total_amp = 0.0;
-
-  for (var o: u32 = 0u; o < params.octaves; o++) {
-    let p = uv * frequency + params.seed;
-    value += noise_2d(p) * amplitude;
-    total_amp += amplitude;
-    frequency *= 2.0;
-    amplitude *= params.amplitude_decay;
-  }
-
-  value /= total_amp;
-  let clamped = clamp(value, 0.0, 1.0);
-
-  textureStore(output_tex, id.xy, vec4f(clamped, clamped, clamped, 1.0));
-}