Module generate 

Code generation (RFC-003 §4, FR-1) and input validation (FR-2).

Generation uses rejection sampling to avoid modulo bias and fails closed on RNG error — never substituting a deterministic or partial value (INV-3).

Functions

generate_code

Generate a fresh plaintext code under policy, drawing randomness from rng.

validate_code_input

Validate and normalize raw user-supplied code input under policy.