Add support for discovering and invoking agent skills from SKILL.md files:
- Skills are auto-discovered from .claude/skills/<name>/SKILL.md (claudecode)
and .gemini/skills/<name>/SKILL.md (gemini)
- New /skills command to list available skills
- Skills can be invoked via /<skill-name> [args...]
- SKILL.md supports optional YAML frontmatter (description, name)
- Full i18n support for 5 languages
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>