Introduces a new 'tools' command that installs development tools (golangci-lint, gotestsum)
by downloading pre-built binaries directly from GitHub releases instead of using 'go get -tool'.
This prevents modifications to plugin go.mod files and improves build reliability.
Features:
- Cross-platform support (Windows, macOS, Linux) with automatic architecture detection
- Version-specific binary naming with symlinks for easy access
- Configurable installation directory via --bin-dir flag
- Tar.gz archive extraction with binary validation
- Updated Makefile integration to use downloaded binaries
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
