Add deployment Docker Compose file, testing utilities, security helpers, and database initialization script

- Introduced `docker-compose.deploy.yml` for deployment scenarios with pre-built Docker images.
- Added `auth_test_utils.py` to simplify authentication testing in FastAPI.
- Implemented `security.py` for token-based operations like file uploads and password resets.
- Created `init_db.py` for database initialization and superuser creation during startup.
- Updated dependencies and tests to support optional authentication in FastAPI.
- Enhanced entrypoint script to handle database initialization.

backend/entrypoint.sh

@@ -4,5 +4,9 @@ echo "Starting Backend"
 
 # Apply database migrations
 alembic upgrade head
+
+# Initialize database (creates first superuser if needed)
+python app/init_db.py
+
 # Execute the command passed to docker run
 exec "$@"