Add new sandbox-sdk skill for building secure code execution environments on Cloudflare. The skill follows the retrieval-led reasoning approach from the Vercel agents.md research, biasing agents towards fetching official docs and examples rather than relying on potentially outdated training data.
- Add sandbox-sdk skill with core patterns, wrangler config, and API guidance
- Include references for detailed API signatures and example mappings
- Add retrieval-first section to durable-objects skill with doc URLs
- Update README with sandbox-sdk in skills table
The sandbox-sdk skill covers getSandbox lifecycle, exec vs runCode decisions, file operations, Dockerfile extensions, preview URLs, and anti-patterns.
The "owner" key is not valid in the Claude Code plugin schema.
The correct key for attribution is "author".
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>