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/.storybook/stories/Breadcrumbs.stories.tsx

@@ -12,10 +12,7 @@ type Story = StoryObj<typeof Breadcrumbs>;
 
 export const Default: Story = {
   args: {
-    items: [
-      { label: 'Scenarios', href: '#' },
-      { label: 'Login flow' },
-    ],
+    items: [{ label: 'Scenarios', href: '#' }, { label: 'Login flow' }],
   },
 };