Module generator 

Replacement generation strategies.

Two concrete implementations:

• HmacGenerator: Deterministic, seeded with a 32-byte key. Same seed + same input = same output across runs. Uses HMAC-SHA256 for domain separation.
• RandomGenerator: Cryptographically random replacements. Non-deterministic.

Both produce category-aware, format-preserving replacements.

Structs

HmacGenerator

Deterministic replacement generator seeded with a 32-byte key.

RandomGenerator

Random replacement generator using OS CSPRNG.

Traits

ReplacementGenerator

Strategy for generating a sanitized replacement value.