docs: update ROADMAP with reverse-reference discovery completion

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

ROADMAP.md

@@ -1469,6 +1469,7 @@ All 313 `@object-ui/fields` tests pass.
 - [x] Collapsible section groups
 - [x] Header highlight area with key fields
 - [x] Console `RecordDetailView` integration: `autoTabs`, `autoDiscoverRelated`, `highlightFields`, `sectionGroups` wired into `detailSchema` for end-to-end availability
+- [x] Console reverse-reference discovery: child objects (e.g., `order_item` → `order`) auto-discovered and rendered with filtered data
 
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