Header Auditor

Write auditHeaders(headers) — headers is an object of response headers. Return an array of missing-hardening findings, checked in this order: no "Content-Security-Policy" => "missing-csp"; no "Strict-Transport-Security" => "missing-hsts"; no "X-Content-Type-Options" => "missing-nosniff"; "X-Frame-Options" not "DENY" (absent counts) => "clickjackable". Empty array = hardened.

Difficulty: intermediate