Create a NUCC taxonomy specialty entry

Creates a new NUCC (National Uniform Claim Committee) taxonomy specialty entry for the tenant. NUCC specialties represent standardized provider taxonomy codes used in claim and credentialing workflows, and are distinct from the general medical specialties managed via POST /specialties.

When to use: Use this endpoint when you need to add a tenant-level NUCC taxonomy specialty record. For general (non-NUCC) specialties use POST /specialties.

Preconditions: Requires the CREATE_SPECIALTY permission. The tenant-id header must be supplied. The request body contains only a data object, which is validated against the NuccSpecialty JSON Schema before storage — a schema violation returns 400. The createdBy and updatedBy audit fields are both automatically set to the authenticated user's ID from the JWT at creation time; they are not accepted in the request body.

Result: Returns 201 with the created NUCC specialty object, including the server-assigned id (a UUID-format string generated by the data layer). Not idempotent — repeat calls create duplicate entries. 400 is returned for either JSON Schema validation failure or a downstream data-layer error.