Ruby C extension wrapping the ML-DSA post-quantum digital signature algorithm (NIST FIPS 204, formerly CRYSTALS-Dilithium). Bundles the PQClean clean C implementation for all three parameter sets: ML-DSA-44 (NIST Level 2), ML-DSA-65 (Level 3), and ML-DSA-87 (Level 5). Supports both hedged (randomized) and deterministic signing modes.