DOC-3340: uc-video elements are not refreshed on undo/redo actions. (#3961)

* DOC-3340: uc-video elements are not refreshed on undo/redo actions.

* DOC-3340: fix syntax issue.

Author: kemister85

modules/ROOT/pages/8.3.2-release-notes.adoc

@@ -41,6 +41,7 @@ For information on the **Media Optimizer** plugin, see: xref:uploadcare.adoc[Med
 
 {productname} {release-version} also includes the following improvement:
 
-=== Placeholder loading had two progress indicators
+=== `uc-video` elements are not refreshed on undo/redo actions
+// #TINY-12884
 
-// TODO: add documentation
+Previously, undo and redo operations rewrote the entire editor content, causing embedded `uc-video` elements to be rewritten and unintentionally refreshed, which disrupted playback and user experience. This behavior affected any content containing `uc-video`, as media elements were reloaded even when unrelated changes were undone or redone. The undo/redo mechanism has been updated to align with the existing iframe handling logic so that, when `uc-video` elements are present, only the modified portion of the content is refreshed rather than the full editor content. As a result, `uc-video` elements now remain stable and are no longer refreshed during undo or redo actions in {productname} {release-version}.