feat: location-Feld an Organisation, Header-Tooltips

- block-types: OrganisationEntry.location { text, lat, lng }
- Header: title-Attribut auf Social-Icons + Suche-Button

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/block-types.ts

@@ -315,6 +315,7 @@ export interface OrganisationEntry {
   badge?: string | { label?: string; color?: string };
   whatsapp?: string;
   youtube?: string;
+  location?: { text?: string; lat?: number; lng?: number };
 }
 
 /** Organisations-Block (_type: "organisations"). */