📝 docs: update existing ADRs with user authentication references

Updated existing Architecture Decision Records:
- Added user authentication references to ADR-0008 (BDD Testing)
- Updated ADR-0016 (CI/CD Pipeline) with authentication workflow
- Enhanced ADR-0017 (Trunk-based Development) with BDD integration
- Added security considerations to multiple ADRs
- Updated cross-references throughout documentation

Removed deprecated files:
- docker-compose.cicd-test.yml (replaced by docker-compose.yml)

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

adr/0009-hybrid-testing-approach.md

@@ -8,7 +8,7 @@
 
 ## Context and Problem Statement
 
-We need to establish a comprehensive testing strategy for DanceLessonsCoach that provides:
+We need to establish a comprehensive testing strategy for dance-lessons-coach that provides:
 - Behavioral verification through BDD
 - API documentation through Swagger/OpenAPI
 - Client SDK validation