Handle Hugo docs information-architecture moves: discover old vs new URLs, add front matter aliases (Phase 1), update in-repo links (Phase 2), interactive List 2 resolution and fragment validation (Phase 3; no guessing). Supports PR-scoped mapping plus whole-content sweeps for inbound links to that mapping, or a full-site follow-up. Triggers on: "IA migration", "redirects for moved pages", "fix links after content move", "PR-scoped link/anchor pass", "aliases for old URLs". After branch work, chain the review-changes skill (main...HEAD) before a PR. Agents must run the in-file required procedure and definition of done, not the phases alone in isolation.