fix: resolve TypeScript type error in formatDate function

- Changed formatOptions typing to Record<string, Intl.DateTimeFormatOptions>
- Separated object creation from indexing to fix type inference
- Resolves incompatible type assignment for DateTimeFormatOptions

src/utils/helpers.ts

@@ -19,13 +19,13 @@ export const formatDate = (
   date: Date,
   format: 'short' | 'medium' | 'long' = 'medium'
 ): string => {
-  const options: Intl.DateTimeFormatOptions = {
+  const formatOptions: Record<string, Intl.DateTimeFormatOptions> = {
     short: { day: '2-digit', month: '2-digit', year: 'numeric' },
     medium: { day: '2-digit', month: 'short', year: 'numeric' },
     long: { day: '2-digit', month: 'long', year: 'numeric' }
-  }[format];
+  };
 
-  return new Intl.DateTimeFormat('fr-FR', options).format(date);
+  return new Intl.DateTimeFormat('fr-FR', formatOptions[format]).format(date);
 };
 
 /**