Why: Preserve the accepted U7 account transaction integration and pin the Backend merge that retains U3 checkpoint behavior.
Evidence: Backend merged main without text conflicts; full Go vet/test and zero-paid live-tag evaluation checks passed. Dev combination and current-head CI will be revalidated.
Impact: Mainline U7 docs/task records and Backend gitlink; no U3 public-contract or model-budget change.
Refs: U3 r0.4 resource-preparation sync; Dev main 05b997b
ui
@ ac5b617e9e