feat: centralise date/time formatting with European conventions

All dates now use day-first ordering (14 Mar 2025) and 24-hour time
(14:30) via a single formatDate.ts module, replacing scattered inline
toLocaleDateString/toLocaleTimeString calls across 12 files.

app/sites/[id]/settings/page.tsx

@@ -7,6 +7,7 @@ import { createGoal, updateGoal, deleteGoal, type Goal } from '@/lib/api/goals'
 import { createReportSchedule, updateReportSchedule, deleteReportSchedule, testReportSchedule, type ReportSchedule, type CreateReportScheduleRequest, type EmailConfig, type WebhookConfig } from '@/lib/api/report-schedules'
 import { toast } from '@ciphera-net/ui'
 import { getAuthErrorMessage } from '@ciphera-net/ui'
+import { formatDateTime } from '@/lib/utils/formatDate'
 import { SettingsFormSkeleton, GoalsListSkeleton, useMinimumLoading, useSkeletonFade } from '@/components/skeletons'
 import VerificationModal from '@/components/sites/VerificationModal'
 import ScriptSetupBlock from '@/components/sites/ScriptSetupBlock'
@@ -1341,7 +1342,7 @@ export default function SiteSettingsPage() {
                               <div className="flex items-center gap-3 mt-1 text-xs text-neutral-400 dark:text-neutral-500">
                                 <span>
                                   Last sent: {schedule.last_sent_at
-                                    ? new Date(schedule.last_sent_at).toLocaleDateString(undefined, { month: 'short', day: 'numeric', year: 'numeric', hour: '2-digit', minute: '2-digit' })
+                                    ? formatDateTime(new Date(schedule.last_sent_at))
                                     : 'Never'}
                                 </span>
                               </div>

app/sites/[id]/uptime/page.tsx

@@ -21,6 +21,7 @@ import { useTheme } from '@ciphera-net/ui'
 import { getAuthErrorMessage } from '@ciphera-net/ui'
 import { Button, Modal } from '@ciphera-net/ui'
 import { UptimeSkeleton, ChecksSkeleton, useMinimumLoading, useSkeletonFade } from '@/components/skeletons'
+import { formatDateFull, formatTime, formatDateTimeShort } from '@/lib/utils/formatDate'
 import {
   AreaChart,
   Area,
@@ -165,11 +166,7 @@ function StatusBarTooltip({
 }) {
   if (!visible) return null
 
-  const formattedDate = new Date(date + 'T00:00:00').toLocaleDateString('en-US', {
-    weekday: 'short',
-    month: 'short',
-    day: 'numeric',
-  })
+  const formattedDate = formatDateFull(new Date(date + 'T00:00:00'))
 
   return (
     <div
@@ -275,10 +272,7 @@ function ResponseTimeChart({ checks }: { checks: UptimeCheck[] }) {
     .reverse()
     .filter((c) => c.response_time_ms !== null)
     .map((c) => ({
-      time: new Date(c.checked_at).toLocaleTimeString('en-US', {
-        hour: '2-digit',
-        minute: '2-digit',
-      }),
+      time: formatTime(new Date(c.checked_at)),
       ms: c.response_time_ms as number,
       status: c.status,
     }))
@@ -500,12 +494,7 @@ function MonitorCard({
                           <div className="flex items-center gap-2">
                             <div className={`w-2 h-2 rounded-full ${getStatusDotColor(check.status)}`} />
                             <span className="text-neutral-600 dark:text-neutral-300 text-xs">
-                              {new Date(check.checked_at).toLocaleString('en-US', {
-                                month: 'short',
-                                day: 'numeric',
-                                hour: '2-digit',
-                                minute: '2-digit',
-                              })}
+                              {formatDateTimeShort(new Date(check.checked_at))}
                             </span>
                           </div>
                           <div className="flex items-center gap-3">