Reassign a report's owner to another active member of the tenant who holds report read access. Requires the TRANSFER_REPORT_OWNERSHIP permission. Used to re-home reports orphaned by user offboarding.

The caller must own the report or have tenant-wide report read access as well as the transfer permission. System-tenant, GLOBAL, SNAPSHOT, SYSTEM, and SYSTEM_COPY reports cannot be transferred. An authorized transfer to the existing owner is a no-op. Missing or inaccessible reports return 404; this does not replace the separate permission and invalid-target responses.