feat: Add Wild Central web app (Central-only UI)

Extract Central pages from the wild-cloud web app into a standalone
React app for Wild Central. Includes:

- Central overview, DNS, DHCP, Firewall, VPN, Ingress, CrowdSec pages
- Simplified sidebar with Central-only navigation
- Branding updated to "Wild Central"
- All Cloud-specific pages, components, hooks, and API services removed
- TypeScript type-check and production build pass

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web/src/App.tsx

@@ -0,0 +1,14 @@
+import { RouterProvider } from 'react-router';
+import { router } from './router';
+import { Toaster } from 'sonner';
+
+function App() {
+  return (
+    <>
+      <RouterProvider router={router} />
+      <Toaster />
+    </>
+  );
+}
+
+export default App;