fix: add missing UI components and utilities

- Add tabs.tsx component
- Add select.tsx component
- Add formatCurrency utility function
- Export new components from index

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/web/components/ui/index.ts

@@ -2,3 +2,5 @@ export { Button, buttonVariants, type ButtonProps } from './button';
 export { Input, type InputProps } from './input';
 export { Card, CardHeader, CardFooter, CardTitle, CardDescription, CardContent } from './card';
 export { Label } from './label';
+export { Tabs, TabsList, TabsTrigger, TabsContent } from './tabs';
+export { Select, SelectTrigger, SelectValue, SelectContent, SelectItem } from './select';