refactor(consolidate): IconButton + Badge-solid + @layer base + Massen-Migration

E: app.css Base-h1–h6 in @layer base → text-*!-Hacks in Titeln entfernt.
Neue Atoms: IconButton (runde Icon-Buttons), Badge solid-Variante + uppercase.

Migrationen (6 parallele Pässe):
- IconButton: 19 runde Nav/Close-Buttons (Carousel, Galleries, QuoteCarousel,
  PostOverview, Organisations, ImageModal).
- Badge: Kategorie/Status-Pills (PostCard, BlogOverview, kalender, Comments,
  CalendarBlock, FilesBlock, SearchableText, Stellingnahme).
- ui-Atome: Formular-Inputs (Comments, termin-melden, Stellingnahme) → TextInput/
  Textarea/Checkbox/SearchField; dunkle NewsletterInline bewusst raw.
- Button-Atom: ~20 inline Buttons in StellingnahmeGeneratorBlock.
- Radius-Sweep: Cards→rounded-lg (viele via .card-surface), Buttons/Inputs→rounded-md,
  Chips→rounded-full; StrommixBlock/Calendar/Files/Adressbuch u.a.

svelte-check 0 errors, voller Prod-Build grün.

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

src/lib/components/blocks/OrganisationsMapBlock.svelte

@@ -144,7 +144,7 @@
   {/if}
 
   <div
-    class="relative h-[320px] overflow-hidden rounded-sm border border-stein-200 sm:h-[clamp(400px,65vh,560px)]"
+    class="relative h-[320px] overflow-hidden rounded-lg border border-stein-200 sm:h-[clamp(400px,65vh,560px)]"
   >
     <!-- Leaflet map fills the container -->
     <div bind:this={mapEl} class="absolute inset-0"></div>