Detects GitHub secret scanning creating an alert for a secret that it has determined is publicly leaked ("github.publicly_leaked == true"). Unlike a generic secret-scanning finding, a publicly leaked secret means GitHub observed the credential exposed outside the repository's access boundary (for example in a public repository, gist, or other public location), so it should be treated as a confirmed credential compromise requiring immediate rotation rather than a low-signal scanner event. Gating on the public-leak flag also removes most of the noise from dummy strings and test fixtures, which are typically confined to private repositories and are not flagged as publicly leaked.