Split the gallery into sections with a divider, start the colored set

Generators now live in gen/<section>/<subject>/<action>.js; the section
folder picks where a tile shows in the gallery and isn't part of the URL.
The first 50 are in gen/bw, a dashed divider follows, then gen/color.

First colored ones: fox/sleep, pig/oink, duck/swim, whale/spout,
turtle/walk, owl/blink, crab/dance, butterfly/flutter, dino/stomp,
jellyfish/pulse.

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

gen/color/butterfly/flutter.js

@@ -0,0 +1,24 @@
+// butterfly fluttering in a little loop, purple and pink wings with yellow spots
+const{sin,cos,PI,abs}=Math,T=2*PI
+export const frames=20,delay=60
+const UP='#b197fc',LO='#faa2c1',SP='#ffd43b',BD='#7048e8'
+export default(c,t)=>{
+  const x=128+20*sin(t*T),y=128+12*sin(2*T*t),r=.12*cos(t*T),s=.22+.78*abs(cos(3*PI*t))
+  const W=(d,f,col)=>{c.save();c.translate(x,y);c.rotate(r);c.scale(d*s,1);c.beginPath();f();c.restore();c.fillStyle=col;c.fill();c.stroke()}
+  for(const d of[-1,1]){
+    c.lineWidth=7
+    W(d,()=>{c.moveTo(0,4);c.bezierCurveTo(50,10,80,44,58,74);c.bezierCurveTo(40,92,6,62,0,12)},LO)
+    W(d,()=>{c.moveTo(0,-6);c.bezierCurveTo(30,-72,100,-62,86,-14);c.bezierCurveTo(80,6,30,6,0,0)},UP)
+    c.lineWidth=4
+    W(d,()=>c.ellipse(58,-30,13,13,0,0,T),SP)
+    W(d,()=>c.ellipse(34,-14,6,6,0,0,T),'#fff')
+    W(d,()=>c.ellipse(40,46,9,9,0,0,T),SP)
+  }
+  c.save();c.translate(x,y);c.rotate(r)
+  for(const d of[-1,1])for(const[w,st]of[[8,'#111'],[3,'#fff']])c.lineWidth=w,c.strokeStyle=st,c.beginPath(),c.moveTo(d*4,-36),c.quadraticCurveTo(d*10,-62,d*22,-66),c.stroke()
+  c.lineWidth=4;c.strokeStyle='#111';c.fillStyle='#fff';for(const d of[-1,1])c.beginPath(),c.arc(d*22,-66,4.5,0,T),c.fill(),c.stroke()
+  c.lineWidth=6;c.fillStyle=BD;c.beginPath();c.ellipse(0,8,8,36,0,0,T);c.fill();c.stroke()
+  c.beginPath();c.arc(0,-34,11,0,T);c.fill();c.stroke()
+  c.fillStyle='#fff';for(const d of[-1,1])c.beginPath(),c.arc(d*4,-35,2.2,0,T),c.fill()
+  c.restore()
+}