fix: Re-export STEP_EXPLANATIONS from StepHeader

VVT and Loeschfristen pages imported STEP_EXPLANATIONS as a named
export from StepHeader.tsx, but it was only imported (not re-exported).
This caused "Cannot read properties of undefined (reading 'vvt')"
at runtime. Adding the re-export fixes both pages.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

admin-compliance/components/sdk/StepHeader/StepHeader.tsx

@@ -5,6 +5,7 @@ import Link from 'next/link'
 import { useRouter } from 'next/navigation'
 import { useSDK, getStepById, getNextStep, getPreviousStep, SDK_STEPS } from '@/lib/sdk'
 import { STEP_EXPLANATIONS } from './StepExplanations'
+export { STEP_EXPLANATIONS }
 
 // =============================================================================
 // TYPES