Add agent skills to the registry catalogue alongside modules and
templates, following the agentskills.io specification with proper
frontmatter metadata (license, version, author, tags).
- Add registry/coder/skills/coder-modules/ and
registry/coder/skills/coder-templates/ as catalogue entries,
each with SKILL.md (full spec frontmatter + body) and README.md.
- Update .agents/skills/ frontmatter to match catalogue versions.
- Update CI/CD workflows and scripts to support skills:
- deploy-registry.yaml: add skills path trigger
- release.yml: detect skills vs modules for changelog path
- version-bump.yaml: add skills path trigger
- version-bump.sh: include skills in change detection
- tag_release.sh: scan skills directories and extract version
from SKILL.md frontmatter