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/main.tsx

@@ -0,0 +1,24 @@
+import { StrictMode } from 'react';
+import ReactDOM from 'react-dom/client';
+import { QueryClientProvider } from '@tanstack/react-query';
+import './index.css';
+import App from './App';
+import { ThemeProvider } from './contexts/ThemeContext';
+import { queryClient } from './lib/queryClient';
+import { ErrorBoundary } from './components/ErrorBoundary';
+
+const root = ReactDOM.createRoot(
+  document.getElementById('root') as HTMLElement
+);
+
+root.render(
+  <StrictMode>
+    <ErrorBoundary>
+      <QueryClientProvider client={queryClient}>
+        <ThemeProvider defaultTheme="light" storageKey="wild-central-theme">
+          <App />
+        </ThemeProvider>
+      </QueryClientProvider>
+    </ErrorBoundary>
+  </StrictMode>
+);