🐛 fix closed async backlog accounting

docs/api/async-logger-dropped-count.md

@@ -36,6 +36,7 @@ Detailed rules explaining key parameters and behaviors
 - The counter increases when overflow policy discards records.
 - The counter can also increase when `close(clear=true)` or `shutdown(clear=true)` abandons queued records.
 - It can also increase when shutdown fallback logic converts remaining pending records into dropped records during a clear-close path.
+- Later log attempts against an already closed queue do not add to this counter by themselves.
 - This is a cumulative counter for the lifetime of the logger value.
 - Use this helper when you need a focused loss metric rather than a full `state()` snapshot.