refactor(adminfront): replace sonner with custom use-toast matching devfront UX policy

adminfront/src/features/tenants/routes/TenantSchemaPage.tsx

@@ -3,7 +3,7 @@ import type { AxiosError } from "axios";
 import { Plus, Save, Trash2 } from "lucide-react";
 import { useEffect, useState } from "react";
 import { useParams } from "react-router-dom";
-import { toast } from "sonner";
+import { toast } from "../../../components/ui/use-toast";
 import { Button } from "../../../components/ui/button";
 import {
   Card,