Runs dead-dependency analysis across JS, Python, and Rust projects using ecosystem-native static tools (`depcheck`/`knip` for JS, `vulture` for Python, `cargo-machete` for Rust), then cross-references the unused-dependency list against SCA findings to downrank vulns in code that is never loaded. Use when SCA output (from `osv-scanner`, `snyk-test`, or `npm-pip-maven-audit`) is too noisy to triage and the team needs to separate unreachable CVEs from exploitable ones before sprint planning; sibling cve-exploitability-triage ranks by EPSS/KEV exploitation signal, not code reachability.