Fail early with a clear message if the variable is missing or lacks
an http(s) scheme.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
The npm sonarqube-scanner bootstrapper was ignoring the host URL and
defaulting to sonarcloud.io. Switch to the official sonar-scanner-cli
binary which respects -D flags directly.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>