Two bugs in yaml-utils.ts toYaml():
1. tools: [] was only emitted when config.tools.length > 0,
but the test asserts it's always present. Add blank-line
separator + unconditional list("tools", ...) so MINIMAL_CONFIG
with tools: [] renders correctly.
2. Nested list values (e.g. runtime_config.required_env: [KEY])
were serialized as " required_env: KEY" (stringification of the
array) instead of a YAML list block. Fix obj() to detect
Array.isArray(sv) and emit a list block with 4-space indent.
Closes#269.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
