- reject non-integer floats in int coerce path
- document masking responsibility on to_public_dict
- use tuple for enum_values (immutable)
- treat empty string as None in normalize_for_compare
Static whitelist of 18 env vars (multimodal, rerank, halacha, general,
credentials, connection) with per-key type coercion, secret masking, and
drift-comparison helpers for the upcoming settings UI.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
