Merge branch 'dev'

CONTRIBUTING.md

backend/alembic/README

backend/app/crud/__init__.py

backend/app/crud/studies.py

backend/app/crud/tasks.py

backend/app/main.py

backend/app/models/__init__.py

backend/app/models/tasks.py

backend/app/routes/decorators.py

backend/app/routes/studies.py

backend/app/routes/tasks.py

backend/app/routes/tests.py

backend/app/schemas/__init__.py

backend/app/schemas/tasks.py

backend/app/schemas/users.py

docker-compose.yaml

docs/cal.com.md

frontend/src/lang/en.json

frontend/src/lang/es.json

frontend/src/lang/fr.json