feat(Paging): extract paging into standalone reusable component

[govind-gs]

Closes #108

Summary

Extracts the inline paging UI from ReadOnlyGrid into a standalone Paging component for easier reuse across grids, lists, and card layouts.

Changes

• New src/components/Paging/Paging.tsx — Standalone paging component with props for startIndex, endIndex, totalCount, currentPage, totalPages, pagingControls, onPageChange, and showWhen
• New src/components/Paging/Paging.stories.tsx — Stories with autodocs, args-based controls, and interactive render (Standard, RowCount, TwoPages)
• New src/components/Paging/index.ts — Barrel export
• Modified src/components/ReadOnlyGrid/ReadOnlyGrid.tsx — Replaced ~40 lines of inline paging UI with <Paging /> usage; removed unused imports
• Modified src/components/index.ts — Added export * from './Paging'

Props

Prop	Type	Default	Description
startIndex	number	—	1-based index of first visible item
endIndex	number	—	Index of last visible item on current page
totalCount	number	—	Total number of items
currentPage	number	—	Current page (1-based)
totalPages	number	—	Total number of pages
pagingControls	'STANDARD' | 'ROW_COUNT'	'STANDARD'	Controls whether total count and first/last buttons show
onPageChange	(page: number) => void	—	Callback when page changes
showWhen	boolean	true	Whether the component is displayed

Behavior

pagingControls	Label format	First/Last buttons
STANDARD	"1 – 10 of many"	Never
ROW_COUNT	"1 – 10 of 50"	When totalPages >= 3

Component returns null when totalPages <= 1.

Screenshots

Standard (pagingControls="STANDARD")

Row Count (pagingControls="ROW_COUNT")

Two Pages (ROW_COUNT, no first/last buttons)

Testing

• TypeScript: ✅ Clean (tsc --noEmit)
• Unit tests: ✅ 50 passed
• Property tests: ✅ 15 passed
• ESLint: ✅ 0 new warnings
• Build: ✅ vite build success