Show error message in admin docs panel instead of staying on Loading

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/admin.js

@@ -3296,8 +3296,14 @@ $('#app-settings-form').addEventListener('submit', async (e) => {
 let adminDocsEditorInstance = null;
 
 async function loadAdminDocs() {
-  const { docs } = await api('/api/admin/docs');
   const el = $('#admin-docs-list');
+  let docs;
+  try {
+    ({ docs } = await api('/api/admin/docs'));
+  } catch (err) {
+    el.innerHTML = `<p class="hint" style="color:red">Error loading documents: ${esc(err.message)}</p>`;
+    return;
+  }
   if (!docs.length) {
     el.innerHTML = '<p class="hint">No submitted documents yet.</p>';
     return;