Update a practitioner's Social Security Number

Updates the Social Security Number for the specified practitioner. This operation requires elevated permission (PRACTITIONER_UPDATE_SSN) beyond standard practitioner update access. Use this only when the SSN on record is incorrect or needs to be set for the first time; SSN is sensitive PII, so access is restricted and audited. {id} is the certifyPractitionerId. The SSN must be exactly 9 plain digits with no dashes or spaces. This operation always writes — there is no read-then-compare, so resubmitting the same value still performs a write.