maquina_credentials 0.1.0

A small, dependency-free gem that encrypts and decrypts a single credentials.yml.enc file with AES-256-GCM. Ships an `mcr` command line tool for reading and writing values, plus a Ruby API. Designed for container and server workflows where the encrypted file travels with the image and the master key is injected at runtime via MAQUINA_MASTER_KEY.