feat: initial backend codebase — EnCoach v3

Complete Odoo 19 backend with 25 custom addons:
- encoach_core: user/entity/role management
- encoach_api: REST API + JWT auth
- encoach_ai: OpenAI integration, AI settings, generation
- encoach_ai_course: AI-powered English & IELTS course generation
- encoach_exam_template/session: exam creation, structures, sessions
- encoach_scoring: AI auto-grading + manual approval
- encoach_vector: pgvector RAG integration
- encoach_adaptive: adaptive learning engine
- encoach_placement: placement testing
- encoach_taxonomy/resources: content taxonomy & resource management
- Plus 14 more modules for courses, branding, portal, etc.

Includes docs: user guide, generation report, developer workflow.

Made-with: Cursor

.gitignore

@@ -0,0 +1,9 @@
+__pycache__/
+*.pyc
+*.pyo
+.env
+*.egg-info/
+.vscode/
+.idea/
+*.swp
+*.swo