Optional
Empty/missing for first writes; required to match on subsequent updates.
TwinfinityMetadataSchema document. Validated against the meta-schema at the API boundary.
Slug ^[A-Za-z0-9_][A-Za-z0-9_-]*$, unique within the parent category.
^[A-Za-z0-9_][A-Za-z0-9_-]*$
Empty/missing for first writes; required to match on subsequent updates.