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, 35 insertions, 0 deletions

diff --git a/src/effects/particle_spray_compute.wgsl b/src/effects/particle_spray_compute.wgsl
new file mode 100644
index 0000000..7bdae88
--- /dev/null
+++ b/src/effects/particle_spray_compute.wgsl
@@ -0,0 +1,35 @@
+struct Particle {
+    pos: vec4f,
+    vel: vec4f,
+    rot: vec4f,
+    color: vec4f,
+};
+
+#include "common_uniforms"
+
+@group(0) @binding(0) var<storage, read_write> particles: array<Particle>;
+@group(0) @binding(1) var<uniform> uniforms: CommonUniforms;
+
+fn hash(p: f32) -> f32 {
+    return fract(sin(p) * 43758.5453);
+}
+
+@compute @workgroup_size(64)
+fn main(@builtin(global_invocation_id) id: vec3u) {
+    let i = id.x;
+    if (i >= arrayLength(&particles)) {
+        return;
+    }
+    var p = particles[i];
+    if (p.pos.w <= 0.0) {
+        let r = hash(f32(i) + uniforms.time);
+        let angle = r * 6.28318;
+        p.pos = vec4f(0.0, 0.0, 0.0, 1.0);
+        p.vel = vec4f(cos(angle), sin(angle), 0.0, 0.0) * (0.5 + hash(r) * 0.5) * (1.0 + uniforms.audio_intensity * 2.0);
+        p.color = vec4f(hash(r + 0.1), hash(r + 0.2), 1.0, 1.0);
+    }
+    let new_pos = p.pos.xyz + p.vel.xyz * 0.016;
+    p.pos = vec4f(new_pos, p.pos.w - 0.01 * (1.0 + uniforms.beat_phase));
+    p.vel.y = p.vel.y - 0.01;
+    particles[i] = p;
+}