This commit refactors the LMS architecture from a flat 2-tier structure to a granular 3-tier structure to support better course organization, while ensuring zero downtime or breaking changes for existing frontend clients.
Introduced `CourseChapter` model as the new grouping layer
2 endpoints (`/v2/.../lessons/`): Introduced new `LessonListV2APIView` and `CourseChapterSerializer` to return the new nested JSON schema (Chapters -> Lessons) for the upcoming accordion UI.
Created robust `migrate_lessons_to_chapters` management command.
Registered `CourseChapter` and added `CourseChapterInline` to `CourseAdmin` for seamless content management.
- Enhanced session handling by checking for active sessions before creating a new room in PlugNMeet, reducing unnecessary API calls.
- Implemented logic to reactivate ended sessions and log relevant actions for better traceability.
- Added conditional room creation to avoid duplicate rooms, improving overall efficiency and user experience.
- Updated CourseLiveSessionRoomCreateAPIView to filter out ended sessions by adding `ended_at__isnull=True` in the session creation logic.
- Introduced a new method in CourseLiveSessionTokenAPIView to build centralized metadata for room settings, ensuring client overrides are not permitted and enhancing session configuration consistency.
- Updated CourseLiveSessionRoomCreateAPIView to filter out ended sessions by adding `ended_at__isnull=True` in the session creation logic.
- Introduced a new method in CourseLiveSessionTokenAPIView to build centralized metadata for room settings, ensuring client overrides are not permitted and defining default lock settings and room features.
