fix admin password reset: send new_password (was password)

The reset endpoint's schema expects new_password; the client sent password,
causing "body.new_password: Field required".

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/api/admin.ts

@@ -38,7 +38,7 @@ export function updateAccess(userId: number, hasAccess: boolean) {
 
 export function resetPassword(userId: number, password: string) {
   return apiClient
-    .put<{ message: string }>(`admin/users/${userId}/password`, { password })
+    .put<{ message: string }>(`admin/users/${userId}/password`, { new_password: password })
     .then((r) => r.data);
 }