NIST Post-Quantum Cryptography Standards (FIPS 203, 204, 205) PQC-2: FIPS 203 ML-KEM Implementation - Module-Lattice Key-Encapsulation Mechanism

Implement FIPS 203 ML-KEM (Module-Lattice-Based Key-Encapsulation Mechanism) based on CRYSTALS-Kyber for key establishment. Use approved parameter sets: ML-KEM-512 (NIST security level 1, 128-bit equivalent) + ML-KEM-768 (level 3, 192-bit) + ML-KEM-1024 (level 5, 256-bit). Implement key generation (KeyGen) + encapsulation (Encaps) + decapsulation (Decaps) per FIPS 203 Sections 5.1 + 5.2 + 5.3. Apply implementation requirements per FIPS 203 Section 6 including correct sampling + rejection sampling + constant-time arithmetic + module-LWE assumptions.