refactor(wgsl): modularize common shader functions

Extracted common WGSL functions into separate files in `common/shaders/` to improve reusability and maintainability.

- Created `common/shaders/render/fullscreen_vs.wgsl` for a reusable fullscreen vertex shader.
- Created `common/shaders/math/color.wgsl` for color conversion and tone mapping functions.
- Created `common/shaders/math/utils.wgsl` for general math utilities.
- Created `common/shaders/render/raymarching.wgsl` for SDF raymarching logic.
- Updated multiple shaders to use these new common snippets via `#include`.
- Fixed the shader asset validation test to correctly handle shaders that include the common vertex shader.

This refactoring makes the shader code more modular and easier to manage.

1 files changed, 1 insertions, 1 deletions

diff --git a/PROJECT_CONTEXT.md b/PROJECT_CONTEXT.md
index 02c51e4..63e6f8a 100644
--- a/PROJECT_CONTEXT.md
+++ b/PROJECT_CONTEXT.md
@@ -34,7 +34,7 @@
 - **Timing System:** **Beat-based timelines** for musical synchronization. Sequences defined in beats, converted to seconds at runtime. Effects receive both physical time (constant) and beat time (musical). Variable tempo affects audio only. See `doc/BEAT_TIMING.md`.
 - **Workspace system:** Multi-workspace support. Easy switching with `-DDEMO_WORKSPACE=<name>`. Organized structure: `music/`, `weights/`, `obj/`, `shaders/`. Shared common shaders in `common/shaders/`. See `doc/WORKSPACE_SYSTEM.md`.
 - **Audio:** Sample-accurate sync. Zero heap allocations per frame. Variable tempo. Comprehensive tests.
-- **Shaders:** Parameterized effects (UniformHelper, .seq syntax). Beat-synchronized animation support (`beat_time`, `beat_phase`). Modular WGSL composition with ShaderComposer. 20 shared common shaders (math, render, compute).
+- **Shaders:** Parameterized effects (UniformHelper, .seq syntax). Beat-synchronized animation support (`beat_time`, `beat_phase`). Modular WGSL composition with ShaderComposer. 24 shared common shaders (math, render, compute).
 - **3D:** Hybrid SDF/rasterization with BVH. Binary scene loader. Blender pipeline.
 - **Effects:** CNN post-processing: CNNEffect (v1) and CNNv2Effect operational. CNN v2: sigmoid activation, storage buffer weights (~3.2 KB), 7D static features, dynamic layers. Training stable, convergence validated.
 - **Tools:** CNN test tool operational. Texture readback utility functional. Timeline editor (web-based, beat-aligned, audio playback).