Config Version Entity
data class ConfigVersionEntity(val version: Long, val createdAtMs: Long, val contentHash: String, val source: String, val abVariant: String?, val signature: String?, val configJson: String, val isActive: Boolean)
Room entity for storing configuration versions.
Data Retention (ISO 27001 A.8.10): Versions are pruned based on maxRetainedVersions policy to limit storage consumption.