Debug: add try/catch and JSON sanitize in saveLesson

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

src/lib/actions/lesson-actions.ts

@@ -22,15 +22,20 @@ export async function saveLesson(
   }
 ) {
   await requireAdmin();
+  try {
     await prisma.lesson.update({
       where: { id: lessonId },
       data: {
         title: data.title,
         kinescopeId: data.kinescopeId || null,
-      content: data.content,
+        content: JSON.parse(JSON.stringify(data.content)),
         published: data.published,
       },
     });
+  } catch (err) {
+    console.error("[saveLesson] full error:", err);
+    throw err;
+  }
   revalidatePath(`/admin/courses/${courseId}/modules/${moduleId}`);
   revalidatePath(`/admin/courses/${courseId}/modules/${moduleId}/lessons/${lessonId}`);
 }