feat: Replace Bootstrap buttons with custom button system
### Custom Button System Implementation
Created modern button system to replace Bootstrap buttons:
- ✅ Created core/_buttons-custom.scss (550+ lines)
- ✅ CSS Custom Properties for easy customization
- ✅ 8 color variants (primary, secondary, success, danger, warning, info, light, dark)
- ✅ Outline and Ghost variants
- ✅ 4 sizes (sm, md, lg, xl)
- ✅ Special variants (block, icon, circle, link)
- ✅ Loading state with spinner animation
- ✅ Button groups support
- ✅ Modern animations (hover, active, focus)
### Template Migration
Migrated 65 HTML templates using automated Python script:
- Replaced .btn → .button
- Replaced .btn-primary → .button--primary
- Replaced .btn-outline-* → .button--outline button--*
- Replaced size classes .btn-sm → .button--sm
- Total changes: 354 → 347 button usages
### Results
- app.css: 137 KB → 148 KB (+11 KB for custom buttons)
- Templates changed: 65 files
- Remaining .btn classes: 133 (mostly btn-close for modals)
- New .button classes: 347
### Backward Compatibility
Kept @extend rules in _buttons-custom.scss for gradual migration.
Can be removed after complete migration.
Next step: Remove Bootstrap button imports from custom-bootstrap.scss
Игорь Надеин
8159c6f472