ci: publish to GitHub Packages on release

[treezio]

Summary

• Adds a GitHub Actions workflow that publishes the package to GitHub Packages on release
• Uses the built-in GITHUB_TOKEN — no external secrets required
• Updates README with GitHub Packages install instructions and npx-based MCP client configs

Release flow

1. Push a version tag (e.g. git tag v1.0.2 && git push --tags) → release.yml creates a draft GitHub Release
2. Review and publish the draft → npm-publish.yml fires and ships to GitHub Packages

Local install (once published)

Add to ~/.npmrc:

@drifthoundhq:registry=https://npm.pkg.github.com
//npm.pkg.github.com/:_authToken=YOUR_GITHUB_PAT

Then use in Claude Code / Claude Desktop config:

{
  "mcpServers": {
    "drifthound": {
      "command": "npx",
      "args": ["-y", "@drifthoundhq/mcp-server"],
      "env": {
        "DRIFTHOUND_API_URL": "https://your-drifthound-instance",
        "DRIFTHOUND_API_TOKEN": "your-token"
      }
    }
  }
}

Note: GitHub Packages requires a GitHub PAT with read:packages scope even for public packages.

🤖 Generated with Claude Code