fix: clean up unused imports in KanbanFilters and backup

- Removed unused `getToday` import from `backup.ts` to streamline the code.
- Cleaned up imports in `KanbanFilters.tsx` by removing `useMemo`, which was not utilized, enhancing readability.

src/services/data-management/backup.ts

@@ -3,7 +3,6 @@ import path from 'path';
 import { prisma } from '@/services/core/database';
 import { userPreferencesService } from '@/services/core/user-preferences';
 import { BackupUtils } from '@/lib/backup-utils';
-import { getToday } from '@/lib/date-utils';
 
 export interface BackupConfig {
   enabled: boolean;