feat: add 6 new audio visualizers

- Vortex: spiral particles pulled toward center, speed reacts to beat
- Starfield: flying through stars with depth parallax and streak effects
- Grid: 3D wave plane with ripple effects from mouse and audio
- Galaxy: 3-arm spiral galaxy with tilted perspective
- Waveform: circular audio waveform in concentric rings
- Kaleidoscope: 8-segment mirrored geometric patterns

All visualizers include:
- GLSL shaders with audio reactivity (low/mid/high frequencies)
- Mouse tracking for interactive parallax
- Beat-synchronized animations

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

assets/js/visualizer/scene.js

@@ -7,12 +7,24 @@ import * as THREE from 'three';
 import { SphereVisualizer } from './particles.js';
 import { TunnelVisualizer } from './tunnel.js';
 import { HelixVisualizer } from './helix.js';
+import { VortexVisualizer } from './vortex.js';
+import { StarfieldVisualizer } from './starfield.js';
+import { GridVisualizer } from './grid.js';
+import { GalaxyVisualizer } from './galaxy.js';
+import { WaveformVisualizer } from './waveform.js';
+import { KaleidoscopeVisualizer } from './kaleidoscope.js';
 
 // Available visualizer classes
 const VISUALIZERS = [
   SphereVisualizer,
   TunnelVisualizer,
-  HelixVisualizer
+  HelixVisualizer,
+  VortexVisualizer,
+  StarfieldVisualizer,
+  GridVisualizer,
+  GalaxyVisualizer,
+  WaveformVisualizer,
+  KaleidoscopeVisualizer
 ];
 
 export class Visualizer {