make-check

Run make check in the project root and report the results.

If any step fails, diagnose the first failure and suggest a fix. Do not proceed to later steps if an earlier one fails — focus on resolving the first issue.

The steps run by make check are:

1. make fmt — gofmt formatting
2. make lint — go vet + golangci-lint
3. make test — all tests with race detector
4. make security — gosec + govulncheck