fix(sessions): make compaction progress bar decorative for a11y

React Doctor flagged the indeterminate compaction bar for using role="progressbar" on a div (prefer-tag-over-role). The bar is decorative — its status is already carried by the visible "Compacting conversation history..." text and the spinner — so drop the role/aria-label and mark it aria-hidden, matching the existing quill-section-loading swoop loader and the decorative spinners in the same feature.

Generated-By: PostHog Code
Task-Id: 1a85695f-6d34-4d9c-9a78-c2f4c836acf4

Author: tatoalo

packages/ui/src/features/sessions/components/session-update/StatusNotificationView.tsx

@@ -150,11 +150,8 @@ function CompactingStatusView() {
           {formatDuration(elapsed, 1)}
         </Text>
       </Flex>
-      <div
-        className="compacting-progress mt-1.5"
-        role="progressbar"
-        aria-label="Compacting conversation history"
-      />
+      {/* Decorative: the spinner and the text above carry the accessible status. */}
+      <div className="compacting-progress mt-1.5" aria-hidden="true" />
     </Box>
   );
 }