Fix CI coverage tool installation without modifying library dependencies. Use plain go mod download and version-pinned go install; tests use -mod=readonly. Go 1.18 jobs use gocover-cobertura v1.2.0; Kafka retains its existing Go 1.26.10/v1.5.0 combination. Helpers report paths match artifact declarations. Only .gitlab-ci.yml changes. YAML validated; converter installation/XML generation previously verified in the corresponding Docker images. No new release tag is required; existing tags retain their original CI configuration.