feat(client): add Timestamp component, ESLint 10 + Prettier, and code quality fixes

- add Timestamp component with moment relative time and ISO tooltip
- add Timestamp stories (JustNow, MinutesAgo, HoursAgo, DaysAgo, MonthsAgo)
- add ESLint 10 with typescript-eslint, react-hooks, react-refresh, prettier
- add Prettier config with singleQuote, semi, trailingComma all, printWidth 100
- add lint, lint:fix, format, test:storybook scripts to package.json
- fix react-hooks/set-state-in-effect in all page components
- auto-fix 113 Prettier formatting issues across src and .storybook

client/src/ui/index.ts

@@ -21,5 +21,8 @@ export type { BreadcrumbsProps, BreadcrumbItem } from './Breadcrumbs/Breadcrumbs
 
 export { ThemeSwitcher } from './ThemeSwitcher/ThemeSwitcher';
 
+export { Timestamp } from './Timestamp/Timestamp';
+export type { TimestampProps } from './Timestamp/Timestamp';
+
 export { Table } from './Table/Table';
 export type { TableProps, TableColumn } from './Table/Table';