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/components/index.ts

@@ -0,0 +1,11 @@
+export { Message } from './Message';
+export { DnsmasqSection } from './DnsmasqSection';
+export { AppSidebar } from './AppSidebar';
+export { ErrorBoundary, ErrorFallback } from './ErrorBoundary';
+export { CentralComponent } from './CentralComponent';
+export { CloudflareComponent } from './CloudflareComponent';
+export { DnsComponent } from './DnsComponent';
+export { DhcpComponent } from './DhcpComponent';
+export { DownloadButton } from './DownloadButton';
+export { CopyButton } from './CopyButton';
+export { HelpPanel } from './HelpPanel';