Metallo Liquido family: liquid-metal chrome tunnel with molten veins

Rounded-square tunnel sections (circle/Chebyshev mix, fbm-wobbled like
molten chrome) flying toward a blinding core; ridged-fbm facets catch a
cool wash from the depth with sparse speculars on periodic section
frames. Molten veins in the palette's complementary colour (Neon: cyan
walls + red veins, like the reference) pump with bass/beat. Shader
family index 58; in the Auto VJ peak pool.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/output.js

@@ -503,7 +503,8 @@ const AV_POOLS = {
     'Fluido', 'Fluido Onda', 'Fluido Vortici', 'Griglia Neon', 'Solidi 3D', 'Tunnel Neon',
     'Onda Luminosa', 'Spettro Neon', 'Onda 3D'],
   peak: ['Julia', 'Iperspazio', 'Tunnel', 'Moiré', 'Fluido Anello', 'Fluido Fuoco',
-    'Vortice', 'Griglia Neon', 'Cristalli', 'Tunnel Neon', 'Tempesta Plasma', 'Spettro Neon']
+    'Vortice', 'Griglia Neon', 'Cristalli', 'Tunnel Neon', 'Tempesta Plasma', 'Spettro Neon',
+    'Metallo Liquido']
 };
 let avMode = 'smart', avFamilies = []; // 'smart' | 'all' | 'custom'
 function avPick(mood) {