Updates an existing seller, addressed by its server-assigned uuid. Functionally equivalent to calling POST /api/v1/sellers with the same external_reference_id (which is the recommended path); this endpoint exists for cases where the integration prefers UUID-addressed updates.

The body cannot change external_reference_id — that field is the upsert key and is set on creation only. To rename a seller externally, register a new one and migrate orders to it.

This endpoint is a full replace: registration_id, vat_id, and contact_email are cleared when omitted from the body. logo_url is the one exception — because the logo is a Mondu-hosted asset mirrored from the URL you submitted, omitting logo_url keeps the current logo so a routine re-sync cannot wipe it. Send a different URL to replace the logo; re-sending an unchanged URL is a no-op.