🎨(front) reorder day header elements

Display day-of-week before day-of-month in calendar column headers
for better visual hierarchy.

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

src/frontend/apps/calendars/src/features/calendar/hooks/useCalendarLocale.ts

@@ -98,7 +98,7 @@ export function useCalendarLocale() {
     const dayOfWeek = date.toLocaleDateString(intlLocale, { weekday: 'short' });
     const dayOfMonth = date.toLocaleDateString(intlLocale, { day: 'numeric' });
     return {
-      html: `<div class="day-header"><span class="day-of-month">${dayOfMonth}</span> <span class="day-of-week">${dayOfWeek}</span></div>`,
+      html: `<div class="day-header"><span class="day-of-week">${dayOfWeek}</span> <span class="day-of-month">${dayOfMonth}</span> </div>`,
     };
   }, [intlLocale]);