Extract the profession↔diploma table out of DiplomaRules into a dedicated
Stamdata.Professions module (business-editable data, separated from the rules
that consume it) and add StamdataValidationTests as the build-time gate: every
seeded diploma program must resolve to a real profession, no blank entries. A
bad edit now fails the build instead of silently rendering "Onbekend". Rules
and behaviour unchanged.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
