feat: Set up Craft-based release workflow for npm and GitHub Releases (#28)

## Summary

Sets up a complete release pipeline using Craft for publishing to npm
and GitHub Releases. Flattens the monorepo structure (moves
`packages/cli/*` to root) and consolidates CI workflows into a single
`ci.yml` with lint, test, and multi-platform builds.

**npm package**: Single-file ESM bundle (~165KB) that works standalone
without dependencies. Replaced `fast-glob` with `tinyglobby` for ESM
compatibility and fixed the bundle to inline all npm packages
(`external: ["node:*"]`). **GitHub Releases**: Native Bun-compiled
binaries for darwin-arm64, darwin-x64, linux-arm64, linux-x64, and
windows-x64. Cross-compilation enabled for platforms without available
CI runners.

**CI improvements**: Consolidated test workflows (removed duplicate
`test.yml`), added coverage reporting, proper `node_modules` caching,
and cross-compilation support via `--target` flag for unavailable
runners (macOS-13 retired, ARM runners not available for private repos).

Author: BYK