Refine AKY24 error simulation and benchmark estimators

[SoraSuegami]

Summary

• Add AKY24 decryption error simulation under src/func_enc/aky24/ with separate PRF-seed refresh bounds, final decode bounds, and PRF mask bit search.
• Reuse shared Goldreich PRG helpers across AKY24 and noise_refresh, including runtime-safe decrypt/recompose paths and targeted unit coverage.
• Update AKY24 keygen/dec benchmark estimators and the poly-circuit evaluator to handle the revised simulation and restricted-output subcircuit path correctly.

Testing

• cargo +nightly fmt --all
• cargo build --lib
• Targeted unit tests for AKY24 error simulation, Goldreich helper behavior, poly-circuit restricted-output evaluation, and noise_refresh simulation
• Ignored AKY24 CRT-depth smoke test passed