Retained output

Honor an explicit user destination. Otherwise, use the project's established durable artifact convention under the resolved CE artifact root; do not invent a second canonical plan. This reference governs a retained document from direct use; chat results and caller-owned artifacts keep their existing delivery contracts.

<!-- ce-docs-root:start --> **Resolve the CE artifact root <root> before composing any artifact path.**

• Read docs_root from <repo-root>/.compound-engineering/config.yaml only (<repo-root> = git rev-parse --show-toplevel). Do not read it from config.local.yaml. Unset -> <root> is docs, exactly as before.
• Validate a set value: a repo-relative directory whose real, symlink-resolved path stays inside the repo and is neither the repo root nor under .git/. Otherwise stop with an error naming docs_root and the value -- never fall back to docs.
• Use <root> as the sole artifact location: create it if absent, compose each path as <root>/<subdir> with this skill's own subdirectory, and never also read docs.

<!-- ce-docs-root:end -->