reconcile-backlog-sweep-plan

Reconcile a backlog-sweep plan's state.json + plan.md against merged/closed PR reality. Use when: multiple backlog-sweep PRs have landed and the plan still shows them as in-review/in-progress, or before picking the next pending initiative to avoid re-shipping already-merged work. Queries gh pr view per initiative, applies merged/deferred transitions, mirrors status into plan.md's table, and commits on a short-lived…