[CMI-James]

Summary of Changes

This pull request adds complete E2E test suites covering admin course management endpoints across issues #653, #652, #651, and #650:

1. Admin Course Archive E2E Tests (Add E2E tests for admin course archive #653) (tests/e2e/admin-course-archive.test.ts):

   • Auth verification (401 unauthenticated, 403 non-admin).
   • Validates archiving active courses sets isActive: false and records archivedAt timestamp.
   • Verifies idempotent archiving preserves original archivedAt timestamp.
   • Tests reactivation / unarchive workflow via course updates.
   • Tests listing and visibility behavior: verifies archived courses are excluded from public listings, while enrolled learners and admins retain access.

2. Admin Course Publish E2E Tests (Add E2E tests for admin course publish #652) (tests/e2e/admin-course-publish.test.ts):

   • Auth verification (401 unauthenticated, 403 non-admin).
   • Tests publish readiness checks via POST /api/v1/admin/courses/:id/publish-check.
   • Tests publish rejection (400 validation error) when blocking issues exist (e.g. course has no modules, or modules lack quizzes).
   • Tests draft to active transition: publishing sets isDraft: false, isActive: true, and clears archivedAt.
   • Verifies published courses immediately appear in the public course catalog.

3. Admin Course Clone E2E Tests (Add E2E tests for admin course clone #651) (tests/e2e/admin-course-clone.test.ts):

   • Auth verification (401 unauthenticated, 403 non-admin).
   • Tests cloning courses with custom titles and fallback default titles (${original.title} (Clone)).
   • Verifies module copying with new IDs while preserving ordering and metadata.
   • Verifies module content items (moduleContent) and module quizzes (quizzes) are deep-copied and remapped to the cloned course and newly generated module IDs.
   • Verifies cloned course initializes in draft state (isDraft: true, isActive: false).

4. Admin Course Import E2E Tests (Add E2E tests for admin course import #650) (tests/e2e/admin-course-import.test.ts):

   • Auth verification (401 unauthenticated, 403 non-admin).
   • Tests multipart/form-data validation and error handling (rejects non-multipart requests, missing file parts, and corrupted/malformed JSON with 400).
   • Tests schema validation against importCourseSchema (rejects missing required fields and invalid difficulty values).
   • Tests successful bulk creation of courses and nested modules from valid uploaded JSON files (returning 201).

Closes #653
Closes #652
Closes #651
Closes #650