Claude Code Everything You Need to Know

What this changes

Checklist (see CONTRIBUTING.md)

• [ ] Date-sensitive claims are anchored to a version (v2.1.x) or full date, with a source link
• [ ] Renamed/removed headings keep an <a id="old-slug"></a> compatibility anchor
• [ ] New skills are tested locally (claude → /your-skill) and documented in docs/skills.md
• [ ] Tables used over walls of bullets; no marketing language