Set/clear the org's HITL approval-UX lines

Set or clear the org's two HITL approval-UX lines (full-replace, PUT semantics).

Both fields are REQUIRED but nullable, so a full-replace can't silently wipe a line by omission: a non-blank string SETS that line; null (or blank) CLEARS it back to the code default; an OMITTED field is a 422 (send the complete desired state, both keys present).

The org's two HITL approval-UX lines, RESOLVED (org value or code default).

Both are always concrete strings: when the org hasn't configured a line, the resolved code default is surfaced so the UI shows exactly what an end-user will see. To revert a line to its default, PUT null for that field.