Concrete codegen implementations targeting ECMAScript (ES module classes). Provides: - EcmaDefinitionCodeGen — emits a JS class declaration mirroring a Java record (or sealed-of-records) ObjectDefinition. - EcmaFunctionsCodeGen — emits a JS TransformationFunctions implementation (transformTo / transformFrom) for the same. Stateless FunctionalObject implementations. The "Codegen as Functions" doctrine — same code runs at build time ...