feat(frist): Deadline-Countdown site-weit + variant-Styling (urgent=rot)

- DeadlineBannerBlock: Farbe nach variant (urgent rot / accent / info / default)
- Layout: deadline-banner-auslegung-2026 site-weit im Bootstrap geladen + oben
  gerendert (vorher nur auf /regionalplan)
- page-regionalplan: inline-Banner entfernt (kein Doppel), Content folgt separat

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/routes/+layout.svelte

@@ -7,6 +7,7 @@
   import Footer from '$lib/components/Footer.svelte';
   import TopBanner from '$lib/components/TopBanner.svelte';
   import AnnouncementBanner from '$lib/components/AnnouncementBanner.svelte';
+  import DeadlineBannerBlock from '$lib/components/blocks/DeadlineBannerBlock.svelte';
   import TranslationProvider from '$lib/components/TranslationProvider.svelte';
   import Breadcrumbs from '$lib/ui/Breadcrumbs.svelte';
   import type { LayoutData } from './$types';
@@ -328,6 +329,9 @@
       class="sr-only focus:not-sr-only focus:fixed focus:top-2 focus:left-2 focus:z-[100] focus:bg-white focus:px-3 focus:py-2 focus:shadow focus:outline focus:outline-2 focus:outline-wald-600 focus:rounded-xs"
     >Zum Inhalt springen</a>
     <div class="flex min-h-screen flex-col text-stein-900">
+      {#if data.deadlineBanner}
+        <DeadlineBannerBlock block={data.deadlineBanner} />
+      {/if}
       {#if data.announcementBanner}
         <AnnouncementBanner banner={data.announcementBanner} />
       {/if}