git:20260713.d505dcd to git:20260922.c37a2ec

4 added, 0 removed. Audit A to A.

# `setup-docs-lint` — technical reference
This composite action provisions the external tools required by the blocking
documentation linter. Both `Static Health Report` and `Documentation Lint`
must call this action before running `scripts/audit/lint_docs.py`.
## Invariants
- `actions/setup-node` and `actions/cache` remain pinned to full SHAs.
+ - `setup-node` enables `cache: npm` (CI-FAST-DOCSLINT-NPM-1): the npm
+ download cache is keyed on the lockfile by the official action; `npm ci`
+ semantics stay unchanged (deterministic reinstall), only tarball
+ downloads are skipped.
- Mermaid diagrams are rendered by the real `mmdc` command against a real
`chrome-headless-shell`; missing tools fail closed.
- The resolved Chrome path is exported through `GITHUB_ENV` for later workflow
steps in the caller job.
- Python setup and `uv sync` remain caller responsibilities.
## Verification
- Run `actionlint` after editing this action or either caller.
- The CI `Documentation Lint` and `Static Health Report` jobs are the real
behavioral controls because the hosted-runner cache and `GITHUB_ENV`
propagation are GitHub Actions behavior.