- Add "by price" sub-mode for per-token pricing (auto-calculate ratios)
- Add color picker with preset colors in tag manager
- Display tags with colors in channel pricing view and selector
- Remove unused function, extract hardcoded color constants
- Fix pricing model filter (status==0 instead of status!=1)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>