documentation

Validate the Hugo documentation site under `docs/` or `site/` for broken links. Builds the site, starts the Hugo server locally, runs Lychee against the rendered HTML using the repo's `lychee.toml`, and reports any broken URLs grouped by source Markdown page. Use locally before pushing changes that touch `docs/**` or `site/**`, when CI's `Check Links` job fails, or whenever the user asks to "check doc links". Read-only with respect to the project sources. Does **not** cover Javadoc/KDoc (out of scope for this skill).

Run the pre-PR checklist for this repo: apply the version gate only when the repository has a root `version.gradle.kts`, run the configured build/check command per `.agents/running-builds.md`, and invoke the configured reviewers (`kotlin-review`, `review-docs`, `dependency-audit`, `check-links`) against the branch diff. On success, write a sentinel file at `.git/pre-pr.ok` so the `gh pr create` hook can verify the checklist ran for the current HEAD. Use before opening a PR, or when CI rejected a branch and you want a fast local repro.