`portainer-cli cp <stack> <container>:<path> <dest>` goes through Docker's
archive API, so unlike `console --run "cat …"` there's no TTY in between and
binary files (database dumps) arrive intact. Works like `docker cp` for files
and directories; a dest of "-" writes a single file to stdout.
Stack and container lookup moves from Console into a shared Resolver module.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
