Reorganize admin into tabbed hubs with a condensed sidebar.

Replace the long flat nav with hub entries, shared AdminHubChrome tabs, and AdminPageShell. Existing URLs stay stable; Settings/Radio and other sections now share one chrome.

Co-authored-by: Cursor <[email protected]>

src/messages/es.json

@@ -719,7 +719,16 @@
 				"backToSite": "Volver al sitio",
 				"housekeeping": "Housekeeping",
 				"hotelManagementPanel": "Panel de gestión del hotel",
-				"rankLabel": "Rango {rank}"
+				"rankLabel": "Rango {rank}",
+				"hubNewsMedia": "News & media",
+				"hubSiteContent": "Site content",
+				"hubEngagement": "Engagement",
+				"hubUsers": "Users",
+				"hubAccess": "Access & security",
+				"hubCatalog": "Catalog & rares",
+				"hubShop": "Shop & payments",
+				"hubTools": "Tools",
+				"hubObservability": "Observability"
 			},
 			"dashboard": {
 				"title": "Panel",