fix(photo-addon): use oCIS locale for all date formatting

Several date formatting calls in PhotosView and usePhotos were using
browser default locale (undefined) instead of the oCIS user's preferred
language. Now consistently uses getUserLocale() from useTranslations
for timeline group labels (week ranges, month names, full dates).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

packages/web-app-photo-addon/src/composables/usePhotos.ts

@@ -269,7 +269,8 @@ export function usePhotos() {
   /**
    * Format date key for display based on mode
    */
-  function formatDateKey(dateKey: string, mode: GroupMode): string {
+  function formatDateKey(dateKey: string, mode: GroupMode, locale?: string): string {
+    const loc = locale || undefined
     const today = new Date()
     const yesterday = new Date(today)
     yesterday.setDate(yesterday.getDate() - 1)
@@ -280,21 +281,21 @@ export function usePhotos() {
       case 'month': {
         const [year, month] = dateKey.split('-').map(Number)
         const date = new Date(year, month - 1, 1)
-        return date.toLocaleDateString(undefined, { year: 'numeric', month: 'long' })
+        return date.toLocaleDateString(loc, { year: 'numeric', month: 'long' })
       }
       case 'week': {
         const [year, weekPart] = dateKey.split('-W')
         const weekNum = parseInt(weekPart)
         const { start: weekStart, end: weekEnd } = getWeekDateRange(parseInt(year), weekNum)
-        return `${weekStart.toLocaleDateString(undefined, { month: 'short', day: 'numeric' })} - ${weekEnd.toLocaleDateString(undefined, { month: 'short', day: 'numeric', year: 'numeric' })}`
+        return `${weekStart.toLocaleDateString(loc, { month: 'short', day: 'numeric' })} - ${weekEnd.toLocaleDateString(loc, { month: 'short', day: 'numeric', year: 'numeric' })}`
       }
       case 'day':
       default: {
         const [year, month, day] = dateKey.split('-').map(Number)
         const date = new Date(year, month - 1, day)
         if (date.toDateString() === today.toDateString()) return 'Today'
         if (date.toDateString() === yesterday.toDateString()) return 'Yesterday'
-        return date.toLocaleDateString(undefined, {
+        return date.toLocaleDateString(loc, {
           weekday: 'long',
           year: 'numeric',
           month: 'long',

packages/web-app-photo-addon/src/views/PhotosView.vue

@@ -224,7 +224,8 @@ const {
 } = usePhotos()
 
 // Initialize translations
-const { $gettext, getMonthNames } = useTranslations()
+const { $gettext, getUserLocale, getMonthNames } = useTranslations()
+const userLocale = getUserLocale()
 
 const clientService = useClientService()
 const spacesStore = useSpacesStore()
@@ -850,7 +851,7 @@ function formatDateHeader(dateKey: string): string {
     startDate.setDate(jan1.getDate() + (weekNum - 1) * 7 - jan1.getDay() + 1)
     const endDate = new Date(startDate)
     endDate.setDate(startDate.getDate() + 6)
-    return `${startDate.toLocaleDateString(undefined, { month: 'short', day: 'numeric' })} - ${endDate.toLocaleDateString(undefined, { month: 'short', day: 'numeric', year: 'numeric' })}`
+    return `${startDate.toLocaleDateString(userLocale, { month: 'short', day: 'numeric' })} - ${endDate.toLocaleDateString(userLocale, { month: 'short', day: 'numeric', year: 'numeric' })}`
   }
 
   const parts = dateKey.split('-')
@@ -861,7 +862,7 @@ function formatDateHeader(dateKey: string): string {
   if (parts.length === 2) {
     // Month: 2026-01
     const date = new Date(parseInt(parts[0]), parseInt(parts[1]) - 1, 1)
-    return date.toLocaleDateString(undefined, { year: 'numeric', month: 'long' })
+    return date.toLocaleDateString(userLocale, { year: 'numeric', month: 'long' })
   }
 
   // Full date: 2026-01-11
@@ -870,7 +871,7 @@ function formatDateHeader(dateKey: string): string {
   if (date.toDateString() === today.toDateString()) return $gettext('Today')
   if (date.toDateString() === yesterday.toDateString()) return $gettext('Yesterday')
 
-  return date.toLocaleDateString(undefined, { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' })
+  return date.toLocaleDateString(userLocale, { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' })
 }
 
 // Handle date filter change - reload photos starting from selected month