Keep images for newer Harness endpoints and retry without it only when an older gateway rejects the field before dispatch. Preserve cancellation and never retry business failures.
Add regression coverage, rebuild the Host bundle, and document the compatibility fix. Follow-up to #75.
The Harness commands execute descriptor declares agentId, line, and images
as required JSON wire fields (strict codec, no acceptsUndefined). The Host
command executor only sent agentId and line, so the Typert gateway rejected
every IM /compact call with arguments-invalid before the command could run.
Send images: [] so /compact works from every IM channel.
