OKF adaptation

This is a low-freedom migration: frontmatter correctness and byte preservation are the contract. Use deterministic scripts for insertion and validation.

Runtime and placement

The canonical source is the package-owned skills/x9-okf-adapt directory and the workflow supports Claude Code and Codex. Migration scripts require Python 3 and Ruby with Psych for strict YAML inspection. Git is optional: timestamp inventory falls back to filesystem modification time when Git history is unavailable.

Scope contract

Operate only on explicitly scoped Markdown files.
Exclude generated/bulk directories and files according to references/okf-format.md.
A complete header contains type, title, description, tags, and timestamp.
A file with partial frontmatter belongs in repair scope; do not classify it as complete.
Preserve every existing valid type, title, description, and tags value by default. A manifest fills missing or invalid fields; replacing a valid semantic field requires the explicit --replace-existing-metadata option. The script preserves a valid timestamp when meaning is unchanged and updates it automatically when an existing header receives a meaning-changing metadata repair.
Preserve the original body bytes, BOM, and line-ending style. Header insertion is the only default mutation.
Repository AGENTS.md, CLAUDE.md, and README changes belong to x9-context-files-generator; README files require --include-readme, and the other onboarding files stay outside this script even when integration is requested.