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

custom_addons/encoach_core/migrations/19.0.1.1/pre-migrate.py

@@ -0,0 +1,13 @@
+"""Placeholder migration script for EnCoach Core v19.0.1.1.
+
+Add actual migration logic here when schema changes are introduced.
+"""
+import logging
+
+_logger = logging.getLogger(__name__)
+
+
+def migrate(cr, version):
+    if not version:
+        return
+    _logger.info('EnCoach Core: pre-migrate from %s', version)