feat(design-system): Storybook + Button-Atom-Vereinheitlichung + SectionHeader

Storybook (SvelteKit-Framework, Tailwind v4, MSW, Translation-Decorator):
Stories für Atoms/Molecules/Organisms + alle CMS-Blocks.

Button-Atom: 5 .btn-*-Varianten (primary/secondary/tertiary/outline/warning),
class-Merge-Prop, href→<a>, Loading-Spinner neben Label, rounded-md/font-medium.
Alle rohen .btn-*- und Hand-Style-Buttons app-weit aufs Atom migriert.

SectionHeader-Molecule (kicker/number/title/subtitle/action) + Integration in
7 CMS-Blocks (post_overview, organisations, organisations_map, searchable_text,
image_gallery, youtube_video_gallery, files) via neuem section_header-Schema.

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

src/lib/components/blocks/CalendarCompactBlock.stories.ts

@@ -0,0 +1,41 @@
+import type { Meta, StoryObj } from '@storybook/sveltekit';
+import CalendarCompactBlock from './CalendarCompactBlock.svelte';
+
+const meta = {
+  title: 'CMS-Blocks/CalendarCompact',
+  component: CalendarCompactBlock,
+  tags: ['autodocs'],
+  argTypes: { block: { control: 'object' } },
+} satisfies Meta<typeof CalendarCompactBlock>;
+
+export default meta;
+type Story = StoryObj<typeof meta>;
+
+const items = [
+  {
+    _slug: 'infoabend',
+    title: 'Infoabend Schleusingen',
+    terminZeit: '2026-08-15T18:00:00Z',
+    location: { text: 'Rathaus Schleusingen' },
+  },
+  {
+    _slug: 'wanderung',
+    title: 'Waldwanderung',
+    terminZeit: '2026-08-23T10:00:00Z',
+    location: { text: 'Parkplatz Waldrand' },
+  },
+  { _slug: 'stammtisch', title: 'Stammtisch', terminZeit: '2026-09-05T19:00:00Z' },
+];
+
+export const Standard: Story = {
+  args: {
+    block: {
+      title: 'Nächste Termine',
+      variant: 'compact',
+      fromPost: false,
+      limit: 3,
+      linkTo: { _slug: 'termine' },
+      items,
+    },
+  },
+};