docs: update ROADMAP.md with DefineApp API persistence and MSW handler

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

Author: Copilot

ROADMAP.md

@@ -491,9 +491,11 @@ ObjectUI is a universal Server-Driven UI (SDUI) engine built on React + Tailwind
 - [x] CommandPalette "Create New App" command (⌘+K → Actions group)
 - [x] Empty state CTA "Create Your First App" when no apps configured
 - [x] `wizardDraftToAppSchema()` conversion on completion
+- [x] `client.meta.saveItem('app', name, schema)` — persists app metadata to backend on create/edit
+- [x] MSW PUT handler for `/meta/:type/:name` — dev/mock mode metadata persistence
 - [x] Draft persistence to localStorage with auto-clear on success
 - [x] `createApp` i18n key added to all 10 locales
-- [x] 11 console integration tests (routes, wizard callbacks, draft persistence, CommandPalette)
+- [x] 13 console integration tests (routes, wizard callbacks, draft persistence, saveItem, CommandPalette)
 
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