config.yaml and config.dev.yml are kept out of git because they can hold
the signing key, but .dockerignore did not leave them out, so a local
copy in the working tree reached the build context and, through
COPY . ., a build-stage layer. .dockerignore now leaves them out in
every directory and in any letter case. configs/config.example.yml is
still sent.
Model: opus-5-5