fix(library): respect locale for cron time display

Derive the clock convention from the active locale so custom scan schedules match the rest of the interface.

Closes #1391

client/src/features/library/components/LibraryCreatorSchedule.vue

@@ -2,11 +2,11 @@
 import { computed } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { Eye } from '@lucide/vue'
-import cronstrue from 'cronstrue'
 import { isFiveFieldCronExpression } from '@bookorbit/types'
 import ToggleSwitch from '@/components/ui/ToggleSwitch.vue'
+import { parseCronToHuman } from '@/features/library/utils/cron'
 
-const { t } = useI18n()
+const { t, locale } = useI18n()
 
 const props = defineProps<{
   watch: boolean
@@ -70,11 +70,8 @@ function humanReadableCron(cron: string | null): string {
     '0 0 * * 1': t('library.creator.schedule.human.weeklyMonday'),
   }
   if (map[cron]) return map[cron]
-  try {
-    return cronstrue.toString(cron)
-  } catch {
-    return t('library.creator.schedule.human.invalid')
-  }
+  const description = parseCronToHuman(cron, locale.value)
+  return !description || description === cron ? t('library.creator.schedule.human.invalid') : description
 }
 </script>
 

client/src/features/library/utils/__tests__/cron.spec.ts

@@ -8,7 +8,7 @@ describe('isFiveFieldCronExpression', () => {
     'accepts %s and previews it',
     (expression) => {
       expect(isFiveFieldCronExpression(expression)).toBe(true)
-      expect(parseCronToHuman(expression)).not.toBe(expression)
+      expect(parseCronToHuman(expression, 'en')).not.toBe(expression)
     },
   )
 
@@ -22,48 +22,55 @@ describe('isFiveFieldCronExpression', () => {
 
 describe('parseCronToHuman', () => {
   it('returns null for null input', () => {
-    expect(parseCronToHuman(null)).toBeNull()
+    expect(parseCronToHuman(null, 'en')).toBeNull()
   })
 
   it('returns null for undefined input', () => {
-    expect(parseCronToHuman(undefined)).toBeNull()
+    expect(parseCronToHuman(undefined, 'en')).toBeNull()
   })
 
   it('returns null for empty string', () => {
-    expect(parseCronToHuman('')).toBeNull()
+    expect(parseCronToHuman('', 'en')).toBeNull()
   })
 
-  it('parses a daily cron to a human-readable string', () => {
-    const result = parseCronToHuman('0 2 * * *')
+  it('uses a 12-hour clock for locales that prefer it', () => {
+    const result = parseCronToHuman('17 14 * * *', 'en')
     expect(result).not.toBeNull()
-    expect(result!.toLowerCase()).toContain('02:00 am')
+    expect(result!.toLowerCase()).toContain('02:17 pm')
+  })
+
+  it('uses a 24-hour clock for locales that prefer it', () => {
+    const result = parseCronToHuman('17 14 * * *', 'nl')
+    expect(result).not.toBeNull()
+    expect(result).toContain('14:17')
+    expect(result).not.toMatch(/am|pm/i)
   })
 
   it('parses an every-5-minutes cron', () => {
-    const result = parseCronToHuman('*/5 * * * *')
+    const result = parseCronToHuman('*/5 * * * *', 'en')
     expect(result).not.toBeNull()
     expect(result!.toLowerCase()).toContain('every 5 minutes')
   })
 
   it('parses a weekly cron', () => {
-    const result = parseCronToHuman('0 0 * * 1')
+    const result = parseCronToHuman('0 0 * * 1', 'en')
     expect(result).not.toBeNull()
     expect(result!.toLowerCase()).toContain('monday')
   })
 
   it('falls back to the raw cron string on invalid input', () => {
     const garbage = 'not-a-cron-at-all'
-    expect(parseCronToHuman(garbage)).toBe(garbage)
+    expect(parseCronToHuman(garbage, 'en')).toBe(garbage)
   })
 
   it('parses a monthly cron', () => {
-    const result = parseCronToHuman('0 0 1 * *')
+    const result = parseCronToHuman('0 0 1 * *', 'en')
     expect(result).not.toBeNull()
     expect(result!.toLowerCase()).toContain('day 1')
   })
 
   it('parses an hourly cron', () => {
-    const result = parseCronToHuman('0 * * * *')
+    const result = parseCronToHuman('0 * * * *', 'en')
     expect(result).not.toBeNull()
     expect(result!.toLowerCase()).toContain('every hour')
   })

client/src/features/library/utils/cron.ts

@@ -1,9 +1,10 @@
 import cronstrue from 'cronstrue'
 
-export function parseCronToHuman(cron: string | null | undefined): string | null {
+export function parseCronToHuman(cron: string | null | undefined, locale: string): string | null {
   if (!cron) return null
   try {
-    return cronstrue.toString(cron, { use24HourTimeFormat: false, verbose: false })
+    const use24HourTimeFormat = new Intl.DateTimeFormat(locale, { hour: 'numeric' }).resolvedOptions().hour12 === false
+    return cronstrue.toString(cron, { use24HourTimeFormat, verbose: false })
   } catch {
     return cron
   }

client/src/features/settings/libraries/components/LibraryAutomationList.vue

@@ -7,14 +7,14 @@ import { parseCronToHuman } from '@/features/library/utils/cron'
 
 const props = defineProps<{ library: Library }>()
 
-const { t } = useI18n()
+const { t, locale } = useI18n()
 
 /**
  * Every setting renders in both states with its real value, so a schedule reads as its actual
  * cron description rather than an icon, and "off" is stated rather than left out.
  */
 const rows = computed(() => {
-  const schedule = parseCronToHuman(props.library.autoScanCronExpression)
+  const schedule = parseCronToHuman(props.library.autoScanCronExpression, locale.value)
   const off = t('settings.admin.libraries.stateOff')
   const on = t('settings.admin.libraries.stateOn')
   return [

client/src/features/settings/libraries/components/LibraryCapabilityStrip.vue

@@ -7,14 +7,14 @@ import { parseCronToHuman } from '@/features/library/utils/cron'
 
 const props = defineProps<{ library: Library }>()
 
-const { t } = useI18n()
+const { t, locale } = useI18n()
 
 /**
  * Every slot renders in both states. An omitted chip and a disabled setting used to look the same,
  * which made a library's configuration unreadable from the list.
  */
 const slots = computed(() => {
-  const schedule = parseCronToHuman(props.library.autoScanCronExpression)
+  const schedule = parseCronToHuman(props.library.autoScanCronExpression, locale.value)
   return [
     { key: 'watch', icon: Eye, on: props.library.watch, label: t('settings.admin.libraries.capability.watch'), detail: null },
     { key: 'schedule', icon: CalendarClock, on: Boolean(schedule), label: t('settings.admin.libraries.capability.schedule'), detail: schedule },