- Add multi-palette theme system using CSS custom properties via data-palette attribute
- Create NeuralCut palette (rose/pink accent #F55385, dark charcoal #1B212B) as default
- Preserve Classic (OpenCut blue) palette as selectable alternative
- Add PaletteSelector component with dark/light toggle and palette picker
- Migrate export button hardcoded colors to theme tokens
- Rebrand all user-visible OpenCut references to NeuralCut across UI
- Update package names and turbo filters for new identity