Describe the feature or problem you'd like to solve

gh skill install currently looks for skills in the following directory patterns:

• skills/*/SKILL.md
• skills/{scope}/*/SKILL.md
• */SKILL.md
• plugins/*/skills/*/SKILL.md

However, many repositories that were built for Claude Code organize their skills under .claude/skills/*/SKILL.md, which mirrors Claude Code's local install location (~/.claude/skills/ and <project>/.claude/skills/). For teams who already maintain shared skills in .claude/skills/ on GitHub, gh skill install <owner>/<repo> fails with:

no skills found in <owner>/<repo>
  Expected skills in skills/*/SKILL.md, skills/{scope}/*/SKILL.md,
  */SKILL.md, or plugins/*/skills/*/SKILL.md
  This repository may be a curated list rather than a skills publisher

Proposed solution

Add .claude/skills/*/SKILL.md (and potentially other host-specific layouts such as .github/skills/, .agents/skills/) to the discovery patterns.

Alternatively, a --path <subdir> or --discovery <glob> flag on gh skill install would let maintainers opt in without requiring repo-layout migration. Prior art: Vercel's npx skills add accepts tree URLs like .../tree/main/<subdir>, and ai-ecoverse/gh-upskill exposes -p/--path.

Why this matters

• Claude Code, GitHub Copilot CLI, and Gemini CLI all document host-specific layouts (.claude/skills/, .github/skills/, .gemini/skills/). Requiring a neutral top-level skills/ forces maintainers to either restructure their repos or maintain parallel trees.
• The --agent claude-code flag already exists on install, so there's precedent for host-aware behavior on the install side. Making discovery host-aware (or just additive with .claude/skills/) closes the loop.

Workaround

Moving/symlinking .claude/skills to skills/ works but splits the source of truth from where Claude Code natively reads skills.

Additional context

• GitHub CLI version: v2.90.x (public preview of gh skill)
• Related doc: https://docs.github.com/en/copilot/how-tos/copilot-cli/customize-copilot/add-skills (mentions .claude/skills as a valid project-scoped location)