Drives the DRC upload's vertrouwelijkheidaanduiding from a new stamdata
table instead of the hardcoded "openbaar", following the existing
config-as-code pattern (ADR-0004). Adds the referential-integrity check
StamdataValidationTests was missing for the new table.
WP-55..60 harden the OpenZaak integration for production (secrets/TLS,
idempotent provisioning, least-privilege scopes, real notifications,
confidentialiteit config, write-divergence resilience). WP-61..66 stand up
a staff-facing behandelportal per ADR-0002, wired to the same backend via
BFF-lite decision DTOs. Both phases are independent tracks; WP-60's
Decisions block is deliberately left open for a planner-agent kickoff.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
eho
