feat: componente SearchBar con debounce y clear

Input de busqueda con icono, debounce configurable y boton de limpiar.
Exportado desde index.ts del barrel de UI.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/functions/ui/index.ts

@@ -114,6 +114,10 @@ export type { TextareaProps } from './textarea'
 export { Toast, ToastProvider, ToastViewport, toastVariants, useToast } from './toast'
 export type { ToastEntry, ToastProps, ToastViewportProps } from './toast'
 
+// Search
+export { SearchBar } from './search_bar'
+export type { SearchBarProps } from './search_bar'
+
 // Hooks — Canvas
 export { useAnimatedCanvas } from './use_animated_canvas'