Function getScreenSize

getScreenSize(width: number): ResponsiveScreenSize
Determine screen size category from viewport width

Categories:
- mobile: < 768px (phones)
- tablet: 768-1024px (tablets)
- desktop: 1024-1440px (standard monitors)
- large: 1440-1920px (HD/2K displays)
- xlarge: ≥1920px (4K/ultra-wide)
Parameters
- width: number
  Viewport width in pixels
Returns ResponsiveScreenSize
Screen size category
Example
```
getScreenSize(375);  // 'mobile'
getScreenSize(768);  // 'tablet'
getScreenSize(1920); // 'xlarge'
```
Korean
화면크기얻기
- Defined in systems/ResponsiveScaling.ts:147