`${VAR:-{}}` appends a stray '}' when VAR is set (bash brace-matching), so the
JSON handed to a caller skill's setup.sh was corrupted and its jq failed with
"Unmatched '}'" — install-caller-skills.sh then caught the non-zero exit and
skipped the skill. Default SECRETS_JSON in two safe steps and pass it as a plain
var. This is why node1-ssh never installed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>