docs: refresh README roadmap (SP4/6/7 shipped, add Next up) + commit SP6 plan
- Mark SP4 as fully shipped (batch diff, search, CSV, a11y all landed) - Add SP6 (Inbox) and SP7 (Per-line reconciliation) sections - Add SP6 + SP7 endpoint inventories - Note next up: outbound 837P serializer The workflow-automation plan was authored but never committed; the features it specified have shipped, so commit it for the historical record alongside this README refresh.
This commit is contained in: