We present QCrypton v4.0, extending the unified quantum-safe security platform with two major capabilities: (1) a Quantum Noise Reachability Engine that classifies noise into 12 sub-types, evaluates against 6 QEC codes (720 evaluations), and recommends optimal correction with 24 compensating controls; and (2) enhanced BB84 eavesdrop detection via statistical noise decomposition, demonstrated catching an eavesdropper at 9.8 sigma when standard BB84 reported "secure." The platform now comprises 12 scanners, post-quantum crypto (FIPS 203/204/205), FTQC cost estimation (28 algorithms), noise reachability, code scanning (6 languages), and automated remediation — all via CLI/SDK/API with zero third-party crypto dependencies.