* fix(cli): init and skills update only touch HyperFrames skills; --skip-skills works
* fix(cli): init never touches installed skills and no command removes one
* fix(cli): shorten the init skills comment
* fix(cli): shorten the init skills comment
* fix(cli): the stale-skills notice reaches agents that run without a terminal
* test(cli): a run without a terminal now checks skills in the background
* fix(cli): the stale-skills notice also prints on --json runs