dienstverlening-aggregator - anonieme infra-voorziening

Endpoints:
  GET /lookup?urn=<urn>      URN-resolver, retourneert record + mock-warn-badge
  GET /aggregator.json       discovery-index van geïndexeerde records
  GET /health                health-check plus harvest-status

Onderbouwing: docs/uitbreidingen/research-rule-and-principle-inferencing/
              03-credential-claim-mapping.md Vraag 3.5 + 3.7