feat: add github skill

skills/github/SKILL.md

@@ -0,0 +1,47 @@
+---
+name: github
+description: "Interact with GitHub using the `gh` CLI. Use `gh issue`, `gh pr`, `gh run`, and `gh api` for issues, PRs, CI runs, and advanced queries."
+---
+
+# GitHub Skill
+
+Use the `gh` CLI to interact with GitHub. Always specify `--repo owner/repo` when not in a git directory, or use URLs directly.
+
+## Pull Requests
+
+Check CI status on a PR:
+```bash
+gh pr checks 55 --repo owner/repo
+```
+
+List recent workflow runs:
+```bash
+gh run list --repo owner/repo --limit 10
+```
+
+View a run and see which steps failed:
+```bash
+gh run view <run-id> --repo owner/repo
+```
+
+View logs for failed steps only:
+```bash
+gh run view <run-id> --repo owner/repo --log-failed
+```
+
+## API for Advanced Queries
+
+The `gh api` command is useful for accessing data not available through other subcommands.
+
+Get PR with specific fields:
+```bash
+gh api repos/owner/repo/pulls/55 --jq '.title, .state, .user.login'
+```
+
+## JSON Output
+
+Most commands support `--json` for structured output.  You can use `--jq` to filter:
+
+```bash
+gh issue list --repo owner/repo --json number,title --jq '.[] | "\(.number): \(.title)"'
+```