Why: branches merged into their immediate or root target had left their task cards open; backfill status and archive to prevent bookkeeping debt.
Evidence: feature-dev-shared-executor-switch.md(PR#600 into main) — merges verified via git log --merges plus Gitea API squash lookup against each card's origin target.
Impact: .task/*.md moved to .task/archive/ with status backfilled; no code or submodule change.
Refs: task.sh close (card-autoclose-r1)