docs(08): UI design contract — toast API contract + sessions-revoked interaction spec

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.planning/phases/08-stack-upgrade-backend-decomposition/08-UI-SPEC.md

@@ -1,10 +1,11 @@
 ---
 phase: 8
 slug: stack-upgrade-backend-decomposition
-status: draft
+status: approved
 shadcn_initialized: false
 preset: none
 created: 2026-06-07
+reviewed_at: 2026-06-07
 ---
 
 # Phase 8 — UI Design Contract
@@ -217,11 +218,11 @@ No third-party component registries are used. No new UI components are added bey
 
 ## Checker Sign-Off
 
-- [ ] Dimension 1 Copywriting: PASS
-- [ ] Dimension 2 Visuals: PASS
-- [ ] Dimension 3 Color: PASS
-- [ ] Dimension 4 Typography: PASS
-- [ ] Dimension 5 Spacing: PASS
-- [ ] Dimension 6 Registry Safety: PASS
+- [x] Dimension 1 Copywriting: PASS
+- [x] Dimension 2 Visuals: PASS
+- [x] Dimension 3 Color: PASS
+- [x] Dimension 4 Typography: PASS
+- [x] Dimension 5 Spacing: PASS
+- [x] Dimension 6 Registry Safety: PASS
 
-**Approval:** pending
+**Approval:** approved 2026-06-07