feat: add StroyBot app shell with URL routing

One web part replaces the separate stroy-bot-* web parts. The section and
its parameters live in the page query string (?page=objects&projectId=5),
so links can be copied, opened in a new tab and the browser Back button works.

- shared config: site/Dataverse/API addresses, list and table names
- HTTP layer behind IHttpClient so repositories can be unit-tested
- ui-kit AppLayout + Sidebar, placeholder for sections not ported yet
- migration checklist with every feature of the old web parts
- design tokens mirrored from ui-kit instead of 8 copies

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

src/webparts/stroyBot/app/PageOutlet.tsx

@@ -0,0 +1,13 @@
+import * as React from 'react';
+import { useRouter } from './routing/RouterContext';
+import { SectionPlaceholder } from './SectionPlaceholder';
+
+/** Показывает страницу текущего раздела. Разделы подключаются сюда по мере переноса. */
+export const PageOutlet: React.FC = () => {
+  const { route } = useRouter();
+
+  switch (route.page) {
+    default:
+      return <SectionPlaceholder />;
+  }
+};