feat: QA fixes, new APIs (assignments, rubrics, custom exams), Generation page enhancements

- Fix ELAI video generation (correct render endpoint, script splitting for 60s limit)
- Fix speaking script generation error handling and empty response display
- Add custom exam list API (GET /api/exam/custom/list)
- Add assignments REST API (list, create, get)
- Add rubrics REST API (list, create)
- Enhance Generation page: dynamic exam structures, auto-module selection, preview dialog, audio player
- Improve submit feedback with exam ID and status in toast notifications
- Fix ExamsListPage to show both custom exams and exam sessions
- Connect RubricsPage to backend API with fallback data
- Add Dockerfile, docker-compose.yml, requirements.txt for deployment
- Fix placement, grading, scoring, and auth controllers
- Add ErrorBoundary component for frontend resilience
- Add QA report and credentials documentation

Made-with: Cursor

backend/custom_addons/encoach_api/__manifest__.py

@@ -5,6 +5,9 @@
     'summary': 'Base controller utilities (JWT auth, response helpers) for EnCoach REST API',
     'author': 'EnCoach',
     'depends': ['base', 'encoach_core'],
+    'external_dependencies': {
+        'python': ['PyJWT'],
+    },
     'data': [],
     'installable': True,
     'license': 'LGPL-3',