thalarch-kotlin-jpalisted

# Thalarch Kotlin JPA Kotlin and ORM semantics interact in ways that generic Java/JPA advice can miss. Treat entity identity, proxying, nullability, generated IDs, lazy associations, equality and serialization as one contract. If the current host exposes the official Kotlin/JetBrains `kotlin-backend-jpa-entity-mapping` skill and the task matches it, prefer loading that skill for platform-specific guidance. This Thalarch skill remains the scope/evidence/verification envelope. ## 1. Prove the persistence stack Before editing, confirm from build files and imports: - Kotlin version and compiler plugins; - JPA package (`javax.persistence` vs `jakarta.persistence`); - ORM/framework and version (Hibernate/Spring Data/etc.); - no-arg/all-open/JPA plugins or equivalent proxy support; - database/migration stack; - serialization/API mapping conventions; - project entity equality/ID conventions. Do not impose a new entity style if the repository already has a deliberate, working convention. ## 2. Entity identity is the primary invariant For every entity define explicitly: - what identifies a persisted instance; - what identifies an unsaved instance; - whether equality is ID-based, business-key-based, or intentionally reference-based; - whether hash code stays safe when persistence state changes; - how proxies/subclasses interact with equality; - whether lazy state can be touched by `equals`, `hashCode`, `toString`, logging or serialization. Do not use Kotlin `data class` for a