Add a comment to a creditor application on behalf of a retailer user

Requires ENQUEUE_RETAILER_CHAT. Obtain userId from GET /users using the same retailer context. The user must be active and belong to the application's retailer, or a retailer group with access to that retailer. The integration remains the audit actor; userId identifies the comment's author. The comment is queued for delivery to the creditor. Archived applications and applications not submitted to the creditor reject comments.

Path Parameters
applicationId uuid — REQUIRED
creditorId uuid — REQUIRED

Header Parameters
X-CreditApp-Retailer-ID uuid

Request Body — REQUIRED
userId uuid — REQUIRED The userId returned by GET /users for the author.
comment string — REQUIRED Possible values: 1 ≤ length Nonblank comment text.

Responses
204 Comment queued for delivery
400 Invalid comment, ineligible user, or application cannot accept comments
401 Authentication required
403 Retailer access or permission denied
404 Application or creditor conversation not found