feat: implement course cloning functionality including chapters, lessons, quizzes, and attachments for instructors.

Backend/src/services/courses.service.ts

@@ -104,6 +104,20 @@ export class CoursesService {
                 where: {
                     id,
                     status: 'APPROVED' // Only show approved courses to students
+                },
+                include: {
+                    chapters: {
+                        select: {
+                            id: true,
+                            title: true,
+                            lessons: {
+                                select: {
+                                    id: true,
+                                    title: true,
+                                }
+                            }
+                        }
+                    }
                 }
             });