feat(sdk): update SDK Flow, Architecture, and StepHeader for vendor-compliance integration

- flow-data.ts: vendor-compliance moved from betrieb/seq:4200 to
  dokumentation/seq:2500, prerequisite changed to vvt, added 5 DB tables
- architecture-data.ts: added vendor tables and API endpoints to
  backend-compliance service definition
- StepHeader.tsx: added vendor-compliance explanation with 4 tips
  (Art. 28, cross-module integration, third-country transfers, controls
  library). Updated obligations (12 checks, vendor-link, document),
  loeschfristen (vendor picker), tom (vendor-controls cross-ref),
  vvt (processor tab from vendor API)

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

admin-compliance/app/sdk/architecture/architecture-data.ts

@@ -160,6 +160,8 @@ export const ARCH_SERVICES: ArchService[] = [
       'security_backlog', 'quality_entries',
       'notfallplan_incidents', 'notfallplan_templates',
       'data_processing_agreement',
+      'vendor_vendors', 'vendor_contracts', 'vendor_findings',
+      'vendor_control_instances', 'compliance_templates',
       'compliance_isms_scope', 'compliance_isms_context', 'compliance_isms_policy',
       'compliance_security_objectives', 'compliance_soa',
       'compliance_audit_findings', 'compliance_corrective_actions',
@@ -178,6 +180,10 @@ export const ARCH_SERVICES: ArchService[] = [
       'CRUD /api/compliance/vvt',
       'CRUD /api/compliance/loeschfristen',
       'CRUD /api/compliance/obligations',
+      'CRUD /api/sdk/v1/vendor-compliance/vendors',
+      'CRUD /api/sdk/v1/vendor-compliance/contracts',
+      'CRUD /api/sdk/v1/vendor-compliance/findings',
+      'CRUD /api/sdk/v1/vendor-compliance/control-instances',
       'CRUD /api/isms/scope',
       'CRUD /api/isms/policies',
       'CRUD /api/isms/objectives',