Close deferred reporting before final delivery

docs/consumers/guide.md

@@ -136,7 +136,9 @@ installation alongside aliases and integration commands.
 `Report()` for formatted substantive values and optional text templates;
 use `Output()` or `RenderOutput()` for deliberate raw output. Use `Warn`, `Info`,
 `Progress`, and `Debug` for categorized messages. Queue a summary with
-`AtEnd().Info` when it belongs after the handler returns. The
+`AtEnd().Info` when it belongs after the handler returns. Deferred submissions
+are accepted until finalization begins; later submissions return
+`ErrReporterClosed`. The
 [CLI reference](../cli.md#reporting) owns flag grammar, visibility, prefixes,
 and status behavior.