docs: add backlog item 999.2 — revamp onboarding flow

.planning/ROADMAP.md

@@ -284,3 +284,11 @@ Plans:
 
 Plans:
 - [ ] TBD (promote with /gsd:review-backlog when ready)
+
+### Phase 999.2: Revamp Onboarding Flow (BACKLOG)
+**Goal**: Redesign the onboarding experience to match the current app style and flow. Replace the manual item edit form with the catalog search function. Visual refresh to align with the newer UI patterns.
+**Requirements**: TBD
+**Plans**: TBD
+
+Plans:
+- [ ] TBD (promote with /gsd:review-backlog when ready)