Add fire, ocean, heartbeat, bounce, trans and storm shaders

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

shaders/heartbeat.glsl

@@ -0,0 +1,19 @@
+// A slow lub-dub travelling up the stairs
+
+float bump(float x, float c, float w) {
+    float d = (x - c) / w;
+    return exp(-d * d);
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    float i = floor(fragCoord.x / iResolution.x * 16.0);
+
+    float period = 3.2;                              // slow, ~19 bpm
+    float ph = fract((iTime - i * 0.15) / period) * period;
+    float beat = bump(ph, 0.50, 0.20) + 0.65 * bump(ph, 1.25, 0.26);
+
+    vec3 base = vec3(0.10, 0.0, 0.01);
+    vec3 col = base + vec3(1.0, 0.04, 0.06) * beat;
+    col += vec3(0.5) * bump(ph, 0.50, 0.08);         // white-ish peak
+    fragColor = vec4(col, 1.0);
+}