ADR-0095: Version_history snapshots every secret-carrying field, with api_key writing no

Status: accepted

Context

A re-enrolled seed is as unrecoverable as a replaced key, and leaving it unversioned is the one option E8 calls unacceptable. Absent field has always meant api_key, and every vault written before this relies on it. The 50-cap stays per entry so a chatty seed cannot evict a key's history

Decision

version_history snapshots every secret-carrying field, with api_key writing no discriminator

Evidence

vault-core/src/lib.rs