refactor(effects): co-locate effect WGSL shaders with their .h/.cc in src/effects/

Move 13 effect-specific shaders from workspaces/main/shaders/ to src/effects/
so each effect's .h, .cc, and .wgsl are together. Update assets.txt paths in
both main and test workspaces. Update EFFECT_WORKFLOW.md to reflect new location.
Shared/reusable snippets remain in src/shaders/.

handoff(Gemini): shaders moved; src/effects/ now has .h, .cc, and .wgsl per effect.

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

1 files changed, 20 insertions, 0 deletions

diff --git a/src/effects/distort.wgsl b/src/effects/distort.wgsl
new file mode 100644
index 0000000..e19bd16
--- /dev/null
+++ b/src/effects/distort.wgsl
@@ -0,0 +1,20 @@
+@group(0) @binding(0) var smplr: sampler;
+@group(0) @binding(1) var txt: texture_2d<f32>;
+
+#include "common_uniforms"
+
+struct DistortParams {
+    strength: f32,
+    speed: f32,
+};
+
+@group(0) @binding(2) var<uniform> uniforms: CommonUniforms;
+@group(0) @binding(3) var<uniform> params: DistortParams;
+
+#include "render/fullscreen_vs"
+
+@fragment fn fs_main(@builtin(position) p: vec4f) -> @location(0) vec4f {
+    let uv = p.xy / uniforms.resolution;
+    let dist = params.strength * uniforms.audio_intensity * sin(uv.y * 20.0 + uniforms.time * params.speed * 5.0);
+    return textureSample(txt, smplr, uv + vec2f(dist, 0.0));
+}