• Renamed PersistentCollection mutating-copy methods to participial forms (add/remove/set/put/clear → adding/removing/setting/putting/clearing and *ed variants) and deprecated the original names #233
• Enabled the Kotlin return-value checker (-Xreturn-value-checker=full) for the core module and annotated select internal helpers with @IgnorableReturnValue where discarding the result is intentional #243
• Updated Kotlin to version 2.3.0 #242
• Configured JDK release to 8 for the Kotlin compiler #239
• Populated Implementation-Title/Implementation-Version/Implementation-Vendor in published JAR manifests #237
• Enabled Dokka documentation generation and upgraded Dokka to 2.2.0 #225, #245, #248