feat: lunar calendar support for countdowns

frontend/src/lib/mvp-utils.ts

@@ -86,6 +86,10 @@ export function countdownKindLabel(kind: string) {
   return ({ countdown: '倒数日', anniversary: '纪念日', birthday: '生日' } as Record<string, string>)[kind] ?? '倒数日'
 }
 
+export function calendarModeLabel(mode: string) {
+  return mode === 'lunar' ? '农历' : '公历'
+}
+
 export function shouldToggleRowSwipe(deltaX: number, deltaY: number) {
   return deltaX >= 64 && deltaX > Math.abs(deltaY) * 1.5
 }