feat: Show Registered Services on Ingress Proxy page

Replace "Instance Routes" with "Registered Services" on the Central
Ingress page. Services are fetched from /api/v1/services and display
name, domain, backend, source, reach level, and backend type.

Central no longer manages instances directly — it shows services
registered by Wild Cloud, Wild Works, and itself.

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

web/src/hooks/useServices.ts

@@ -0,0 +1,17 @@
+import { useQuery } from '@tanstack/react-query';
+import { servicesApi } from '../services/api/networking';
+
+export const useServices = () => {
+  const query = useQuery({
+    queryKey: ['services'],
+    queryFn: () => servicesApi.list(),
+    refetchInterval: 30000,
+    staleTime: 10000,
+  });
+
+  return {
+    services: query.data?.services ?? [],
+    isLoading: query.isLoading,
+    error: query.error,
+  };
+};