Project-local Deno skills

These skills were copied from https://github.com/denoland/skills Upstream commit: 1a4267f4fc60d75839d740ae39a7e0bb0170cf0b Installed into .github/skills for repo-local agent-skill support.

Included skills:

• deno-guidance
• deno-deploy
• deno-frontend
• deno-sandbox
• deno-project-templates
• deno-expert

Notes for this repo:

• This project is intended to become a Deno progressive web app for mobile-native Shikaku.
• Deno Deploy is the target hosting platform.
• Favor first-party Deno options when possible.

If you want, I can next scaffold the actual app structure for a daily-puzzle PWA.