ASSET_REGISTRY.json: machine-readable sweep of entire codebase
- 67 emojis with exact file:line locations
- 80 unique colors
- 14 gradients
- 24 animations
- 56 CSS variables

Admin panel new sections:
- 🧃 Juice Settings: particles on/off, shake intensity, haptic, confetti count,
  coin fly count, bounce scale, slam scale, float amount
- 😀 Emoji Replacements: 27 most visible emojis as upload slots
  Each with: current emoji preview, size hint, usage description
  Upload SVG/PNG → replaces emoji throughout the app

theme.js updated:
- emoji() helper: returns uploaded image OR fallback emoji at exact size
- image-rendering: -webkit-optimize-contrast (fixes pixelation on non-retina)
- All images use object-fit:contain (never overflow their expected box)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>