feat(ADM-019): completed feature

backlog/features.json

@@ -185,7 +185,7 @@
       "id": "ADM-019",
       "title": "Admin: Customer Detail",
       "description": "Detalle de cliente con pedidos y direcciones.",
-      "status": "pending",
+      "status": "done",
       "priority": "medium",
       "phase": "customers",
       "created_at": "2026-08-16T22:13:57Z",
@@ -195,7 +195,8 @@
         "qa": true,
         "close": true
       },
-      "type": "feature"
+      "type": "feature",
+      "completed_at": "2026-08-17T20:31:31Z"
     },
     {
       "id": "ADM-020",