normalize agents files

[radium-v]

Pull Request

📖 Description

Normalizes agent and AI-tooling configuration files to a shared, tool-agnostic layout so that Copilot, Claude, and other agents read from a single source of truth.

• Moves the skills directory from .github/skills/ to .agents/skills/ and updates internal path references accordingly.
• Renames .github/copilot-instructions.md to AGENTS.md as the canonical instructions file.
• Points CLAUDE.md to AGENTS.md as a symlink
• Stubs out .claude/skills/* to point to respective .agents/skills/ files

✅ Checklist

General

• I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation and followed the standards for this project.

[radium-v]

The motivation behind this change is to provide compatibility with the Github CLI command, which will allow people to install our skills and use them in their projects (see https://cli.github.com/manual/gh_skill_install). There may be more changes necessary to facilitate it.

[janechu]

This structure seems like a good direction and more agent-friendly overall: AGENTS.md at the repo root plus .agents/skills/ gives us a tool-neutral source of truth that should be easier for multiple agents to discover than keeping everything under .github/.

A few things I think we should tighten up before relying on it:

1. Compatibility: should we keep .github/copilot-instructions.md as a shim or symlink to AGENTS.md? That would avoid regressing any Copilot surface that still reads the existing GitHub-specific instructions file rather than AGENTS.md.
2. Claude skill stubs: can we confirm the one-line @../../../.agents/... files in .claude/skills/*/SKILL.md are actually resolved as skill content by Claude? If not, symlinks or generated real files would be safer.
3. Beachball ignore config: .agents/skills/ was added to the shipping skill as ignored, but beachball.config.js still only ignores .github/. We should update the config too so the docs and behavior match.