Fix admin tests endpoint to create_manual and fix language enum from EN to English

src/app/admin/tests/page.tsx

@@ -45,7 +45,7 @@ export default function AdminTestsPage() {
 
   const handleToggle = async (testId: string) => {
     try {
-      const res = await fetch(`http://localhost:8000/api/admin/tests/${testId}/toggle`, {
+      const res = await fetch(`/api/admin/tests/${testId}/toggle`, {
         method: "PUT"
       })
       if (res.ok) {
@@ -83,7 +83,7 @@ export default function AdminTestsPage() {
     };
 
     try {
-      const res = await fetch("/api/admin/tests/upload", {
+      const res = await fetch("/api/admin/tests/create_manual", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify(payload)