Remove default layout, migrate all pages to topnav

- Add layout: 'topnav' to all 27 pages that were using default layout
- Delete app/layouts/default.vue

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/pages/catalog/hubs/[id].vue

@@ -112,6 +112,10 @@ import { GetLocationOffersDocument, GetSupplierProfilesDocument } from '~/compos
 import { GetNodeConnectionsDocument, GetAutoRouteDocument, GetRailRouteDocument } from '~/composables/graphql/public/geo-generated'
 import type { EdgeType } from '~/composables/graphql/public/geo-generated'
 
+definePageMeta({
+  layout: 'topnav'
+})
+
 interface RouteGeometry {
   toUuid: string
   coordinates: [number, number][]