feat: add dismissible domain migration notice

src/routes/+layout.svelte

@@ -2,6 +2,7 @@
   import { onMount } from 'svelte';
   import { page } from '$app/stores';
   import AnalyticsConsent from '$lib/components/AnalyticsConsent.svelte';
+  import DomainMigrationNotice from '$lib/components/DomainMigrationNotice.svelte';
   import { events } from '$lib/data/events.ts';
   import { createInitialReleaseClock, synchronizeReleaseClock } from '$lib/data/release-clock.ts';
   import { activeEventAt } from '$lib/engine/event-optimization.ts';
@@ -26,6 +27,8 @@
   });
 </script>
 
+<DomainMigrationNotice />
+
 <header class="site-nav">
   <div class="nav-inner">
     <a class="brand" href="/" aria-label="홀로도리 계산기 홈">홀로도리 계산기</a>