Standalone utility skill (manual /wiki, not a pipeline phase). Fixes the house rules for repository-wiki articles: durable project-neutral knowledge only (no implementation state — that belongs in docs/), every load-bearing fact backed by a validated external source, claims marked law/convention/corrected, an overview page plus cross-linked detail pages each with a References section, written in English. Documents the wiki mechanics (own <repo>.wiki.git, slugs, edit paths, special files) and the wiki-vs-docs/ decision rule.
README: list `wiki` among the on-demand utility skills, kept out of the pipeline table.
