feat(export): Bestandsbuch für Tierarzneimittel nach Art. 108 VO (EU) 2019/6

- Treatment records supplier, purchase proof and prescribing vet, and
  keeps the apiary the colony stood at on the treatment day.
- Holder name and address in site settings (never in public output;
  regression test in public.service.spec).
- treatment-log.pdf: one sheet per apiary, identical treatments grouped,
  missing mandatory fields printed as FEHLT, uncertain locations marked.
- Shared PDF table helpers extracted from the record card.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Frontend/src/lib/site-settings/types.ts

@@ -4,6 +4,8 @@ export interface SiteSettings {
   instagramUrl: string | null;
   tiktokUrl: string | null;
   websiteUrl: string | null;
+  holderName: string | null;
+  holderAddress: string | null;
   updatedAt: string;
 }
 
@@ -12,4 +14,6 @@ export interface UpdateSiteSettingsInput {
   instagramUrl?: string;
   tiktokUrl?: string;
   websiteUrl?: string;
+  holderName?: string;
+  holderAddress?: string;
 }