- Add .golangci.yml configuration enabling govet, staticcheck, errcheck, gosimple, ineffassign, unused, gofmt, and goimports linters
- Update scripts/check.sh to run golangci-lint with go vet fallback
- Update CI workflow to install golangci-lint in both format and quality jobs
- Add golangci-lint to CONTRIBUTING.md setup instructions
Closes#266
