Claude Code 2.1.88+ deprecated commands/ subdirectory discovery in favor of
skills/*/SKILL.md format. This migrates the Claude Code installer to use the
same skills pattern already used by Codex, Copilot, Cursor, Windsurf, and
Antigravity.
Key changes:
- New convertClaudeCommandToClaudeSkill() preserving allowed-tools and argument-hint
- New copyCommandsAsClaudeSkills() mirroring Copilot pattern
- Install now writes skills/gsd-*/SKILL.md instead of commands/gsd/*.md
- Legacy commands/gsd/ cleaned up during install
- Manifest tracks skills/ for Claude Code
- Uninstall handles both skills/ and legacy commands/
Fixes#1504
Supersedes #1538
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>