Effects engine, SVG/VU/silhouette categories, pad bank, MP4 recording, dual-window UI

- Parametric effect engine: 23 shader families × palettes × variants (~2300 presets)
  with a filterable library and an effect sequence (auto-cycle by time or beat).
- Effect categories: fractals/abstract, dancing silhouettes, SVG/Image source
  (loads any SVG/image as a recolourable audio-reactive effect; 50+ bundled CC0 SVGs),
  and VU-Meter (32-band spectrum bars, analogue needle, stereo LEDs).
- Dual-window architecture: control panel + fullscreen output on an external display
  (reliable via simple-fullscreen); tabbed control UI (Audio, Effetti, Pad, Immagini,
  Testo, Registra, Schermo).
- Audio: file playback + live input + output device selection, per-band visual EQ,
  audio playlist (reorder, hotkeys, per-track play/pause, repeat).
- Pad bank: 5×4 launchpad with persistent assignments; pressing a pad stops the current.
- Overlays: slideshow images (resizable), two freely positioned/resizable logos,
  scrolling ticker text.
- MP4 recording of the composited output (visual + overlays + audio) via MediaRecorder
  + ffmpeg, with selectable aspect ratios (16:9, 9:16, 1:1, 4:3, 3:4, 21:9).
- App icon (.icns) and dock icon; author Dj LuZa.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/output.html

@@ -13,6 +13,10 @@
   <!-- Image overlay layer -->
   <div id="overlay-images"></div>
 
+  <!-- Two independent, freely-positioned & resizable logos -->
+  <img id="logo-0" class="logo" />
+  <img id="logo-1" class="logo" />
+
   <!-- Scrolling text ticker -->
   <div id="ticker"><div id="ticker-track"><span></span><span></span></div></div>
 
@@ -22,6 +26,7 @@
   </div>
 
   <script src="shaders.js"></script>
+  <script src="effects.js"></script>
   <script src="visualizer.js"></script>
   <script src="audio.js"></script>
   <script src="output.js"></script>