Update API endpoints and navigation paths in admin templates

internal/web/templates/admin/index.html

@@ -98,7 +98,7 @@ async function sendAction(action) {
     if (!currentMedia?.id) return;
 
     const token = getToken();
-    const endpoint = `admin/api/${action}`;
+    const endpoint = `api/${action}`;
     await fetch(endpoint, {
         method: 'POST',
         headers: {
@@ -130,7 +130,7 @@ function showMessage(text) {
 }
 
 async function fetchMedia(token) {
-    const res = await fetch('admin/api/getmedia', {
+    const res = await fetch('api/getmedia', {
         method: 'GET',
         headers: { 'Authorization': 'Bearer ' + token }
     });