📝 refine async state snapshot docs

docs/api/async-logger-state-new.md

@@ -55,6 +55,7 @@ Detailed rules explaining key parameters and behaviors
 - It also does not validate whether the supplied fields represent a combination that could come from one real logger instant.
 - The constructed value matches the same public shape used by async logger serializers.
 - Because `AsyncLoggerState` is only a data snapshot type, this constructor is mainly useful for tests, adapters, and synthetic diagnostics rather than ordinary logger inspection.
+- Serialization helpers accept any `AsyncLoggerState` value, including hand-built ones from this constructor.
 
 ### How to Use