fix(web): use locale for date picker (#26125)

web/src/lib/stores/preferences.store.ts

@@ -9,7 +9,7 @@ export interface ThemeSetting {
 }
 
 // Locale to use for formatting dates, numbers, etc.
-export const locale = persisted<string | undefined>('locale', 'default', {
+export const locale = persisted('locale', 'default', {
   serializer: {
     parse: (text) => text || 'default',
     stringify: (object) => object ?? '',

web/src/routes/+layout.svelte

@@ -13,6 +13,7 @@
   import { themeManager } from '$lib/managers/theme-manager.svelte';
   import ServerRestartingModal from '$lib/modals/ServerRestartingModal.svelte';
   import { Route } from '$lib/route';
+  import { locale } from '$lib/stores/preferences.store';
   import { sidebarStore } from '$lib/stores/sidebar.svelte';
   import { user } from '$lib/stores/user.store';
   import { closeWebsocketConnection, openWebsocketConnection, websocketStore } from '$lib/stores/websocket';
@@ -23,6 +24,7 @@
     CommandPaletteDefaultProvider,
     TooltipProvider,
     modalManager,
+    setLocale,
     setTranslations,
     toastManager,
     type ActionItem,
@@ -52,6 +54,8 @@
     });
   });
 
+  $effect(() => setLocale($locale));
+
   let { children }: Props = $props();
 
   let showNavigationLoadingBar = $state(false);