chore: add build and distribution pipeline

[oliyy]

What changed

• add a GoReleaser-based release pipeline for GitHub release archives and checksums
• add Homebrew tap and Scoop bucket publishing config for tagged releases
• add maintainer make targets plus a pinned GoReleaser bootstrap script for local verification
• add CI and release GitHub Actions workflows
• document installation and release setup in both READMEs

Why

This prepares the project for open-source releases with a repeatable path for local verification, tagged binary releases, and package-manager distribution.

Impact

• tagged releases can publish archives for macOS, Linux, and Windows
• Homebrew tap and Scoop bucket updates are wired through GoReleaser once the target repos and token are in place
• maintainers get make verify and make release-snapshot as the main local checks

Validation

• make verify
• make release-snapshot