convertEntriesValueOrNull
inline fun <KS : Any, VS : Any, KT : Any, VT : Any> Map<KS, VS?>.convertEntriesValueOrNull(path: String, keyFrom: String, keyTo: String, valueFrom: String, valueTo: String, convertKey: (KS) -> KT?, convertValue: (VS) -> VT?): Map<KT, VT?>
Map<K, V?> (nullable target values): null source value → null-in-place, silent; broken value → null-in-place + MappingDegradation.AbsorbedConversionError with the TYPED cause carrying valueFrom→valueTo; broken key → drop entry + MappingDegradation.DroppedBrokenElement carrying keyFrom→keyTo; sanctioned-null key → silent drop; key collision → reported, value still written (last wins). Only Exceptions are absorbed: CancellationException and Errors always propagate.