[ademboukabes]

Summary

Closes #51.

Introduces automated test coverage reporting in CI and local developer workflows:

• Generates Go coverprofile with atomic mode and race detection (go test -race -coverprofile=coverage.out -covermode=atomic ./...).
• Generates an instant Markdown coverage summary per package rendered in GitHub Step Summary ($GITHUB_STEP_SUMMARY).
• Uploads coverage to Codecov via codecov/codecov-action@v5 (non-blocking if secret is absent).
• Exports interactive HTML and raw coverage reports as CI build artifacts (actions/upload-artifact@v4).
• Provides developer-friendly Makefile targets (make test-coverage and make coverage-html).

What changed

1. GitHub Actions Workflow (.github/workflows/ci.yml):

   • Replaced plain go test -race ./... with atomic coverprofile generation.
   • Added ./scripts/coverage-summary.sh coverage.out step to emit a clean Markdown summary table into $GITHUB_STEP_SUMMARY.
   • Added codecov/codecov-action@v5 step with fail_ci_if_error: false.
   • Added actions/upload-artifact@v4 step archiving coverage.out and coverage.html (14 days retention).

2. Portable Summary Script (scripts/coverage-summary.sh):

   • Portable POSIX sh/awk script computing overall statement coverage and per-package breakdown.
   • Categorizes packages with plain text status tags (GOOD >= 70%, WARN 30-69%, LOW < 30%).
   • Appends directly to $GITHUB_STEP_SUMMARY in CI, prints to stdout for local execution.

3. Makefile & Tooling (Makefile, .gitignore):

   • Added make test-coverage (runs tests with coverprofile and displays report).
   • Added make coverage-html (generates browser-viewable coverage.html).
   • Added coverage.html to .gitignore.

4. Documentation (CONTRIBUTING.md, docs/BACKLOG.md):

   • Documented make test-coverage and make coverage-html in CONTRIBUTING.md.
   • Marked coverage reporting as shipped in docs/BACKLOG.md.

Verification

• make test-coverage: PASS (100% tests pass with race detector, overall statement coverage: 68.2%)
• make lint (go vet ./... + golangci-lint run ./...): PASS (0 issues)
• make build: PASS
• ./mctf -C examples/sample-event validate: PASS
• ./mctf -C examples/sample-event generate --check: PASS