True style synthesizer, success effects, granular intro, dark selects

- New style button now runs a 12-gene genome renderer (6 fields x 5
  domain geometries x 4 color maps x 4 shading models x 4 overlays)
  producing standalone styles instead of blending existing modes
- Share codes v3 carry the genome, v1/v2 codes still decode
- Download completion fires a palette-colored particle burst, pulse
  ring and animated success check toast
- Intro animation staggers every individual control, compositor-only
- color-scheme dark fixes white native select dropdowns in modals
- Sharper liquid-glass diamond favicon and touch icons

Co-authored-by: Cursor <cursoragent@cursor.com>

js/modals.js

@@ -250,8 +250,8 @@ var Modals = (function () {
       a.download = "lumen-set-" + MODES[P.mode].key + ".zip";
       a.click();
       setTimeout(function () { URL.revokeObjectURL(a.href); }, 4000);
-      UI.toast("Set saved: " + entries.length + " PNGs (" + w + "\u00d7" + h + ")");
       close();
+      FX.celebrate("Set saved: " + entries.length + " PNGs (" + w + "\u00d7" + h + ")");
     });
 
     await build();