What problem does it solve? Project documentation drifts out of sync with code as commits accumulate. This Skill audits README, CHANGELOG, and AGENTS.md/CLAUDE.md agent handbooks against a reproducible Git range, then updates, merges, or deletes stale content under explicit scope confirmation. ## Core Features & Use Cases - Reproducible Git-range auditing: Resolves the last sync baseline from a versioned state file, diffs FROM_SHA..INPUT_HEAD, and maps changes to documentation lifecycle actions (add, update, delete, merge, keep, propose-only). - Agent handbook maintenance: Incrementally maintains or fully rebuilds AGENTS.md trees with manifest discovery, role classification (repo-root, aggregator, runnable-app, capability-module, contract-module, scripts-docs), and fixed CLAUDE.md redirects. - README and CHANGELOG contracts: Enforces a nine-section README structure with an English README.md plus mirrored README-ZH.md, and Keep a Changelog conventions derived from actual diffs rather than commit messages. - Use Case: After a sprint of merged pull requests, run the Skill to checkpoint the workspace, confirm documentation scope, regenerate stale agent handbooks, and commit synchronized docs with an auditable report and state file. ## Quick Start Ask the agent to run docs-sync to audit all project documentation against the commits since the last sync and update the README, CHANGELOG, and AGENTS.md files accordingly.