Keep the dedicated workspace-copyback transaction active with bounded SELECT 1 probes while filesystem work runs. Preserve existing connection, owner-token, takeover and publication fences.
Verified head 7fb0ad45bf: full CI, E2E, Superagent, legacy statuses and Apex 5/5; no unresolved review findings. Real PostgreSQL idle-timeout reproduction and 71 affected cases pass. Strengthened disabled-timeout controls fail when their guard is removed.
Co-Authored-By: Paperclip <noreply@paperclip.ing>