makefile-awk-help-target-regex-excludes-digits

A common Makefile self-documenting help pattern uses awk to extract targets + comments. The default regex pattern [a-zA-Z_-] excludes digits, silently dropping targets like test-a11y, k8s-apply, prod-up from make help output. Fix: extend character class to [a-zA-Z0-9_-] in the awk match expression.