feat: port stroy-bot-objects as objects page

Project object tree with add/edit/delete, drag & drop re-parenting,
context menu and Excel export, 1:1 with the legacy web part. The tree
widgets live in pages/_tree so the works page can reuse them.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/webparts/stroyBot/app/PageOutlet.tsx

@@ -6,6 +6,7 @@ import { ResourcesPage } from '../pages/resources/ResourcesPage';
 import { BinderPage } from '../pages/binder/BinderPage';
 import { ReportsPage } from '../pages/reports/ReportsPage';
 import { ImportWorksPage } from '../pages/import/ImportWorksPage';
+import { ObjectsPage } from '../pages/objects/ObjectsPage';
 
 /** Показывает страницу текущего раздела. Разделы подключаются сюда по мере переноса. */
 export const PageOutlet: React.FC = () => {
@@ -22,6 +23,8 @@ export const PageOutlet: React.FC = () => {
       return <ReportsPage />;
     case 'import':
       return <ImportWorksPage />;
+    case 'objects':
+      return <ObjectsPage />;
     default:
       return <SectionPlaceholder />;
   }