[FIX] Add tooltips to Thread header buttons (#20456)

app/threads/client/components/ThreadView.tsx

@@ -36,7 +36,7 @@ const ThreadView = forwardRef<Element, ThreadViewProps>(({
 
 	const t = useTranslation();
 
-	const expandLabel = expanded ? t('collapse') : t('expand');
+	const expandLabel = expanded ? t('Collapse') : t('Expand');
 	const expandIcon = expanded ? 'arrow-collapse' : 'arrow-expand';
 
 	const handleExpandActionClick = useCallback(() => {
@@ -69,9 +69,9 @@ const ThreadView = forwardRef<Element, ThreadViewProps>(({
 				<VerticalBar.Header>
 					<VerticalBar.Icon name='thread' />
 					<VerticalBar.Text dangerouslySetInnerHTML={{ __html: title }} />
-					{hasExpand && <VerticalBar.Action aria-label={expandLabel} name={expandIcon} onClick={handleExpandActionClick} />}
+					{hasExpand && <VerticalBar.Action title={expandLabel} name={expandIcon} onClick={handleExpandActionClick} />}
 					<VerticalBar.Actions>
-						<VerticalBar.Action aria-label={followLabel} name={followIcon} onClick={handleFollowActionClick} />
+						<VerticalBar.Action title={followLabel} name={followIcon} onClick={handleFollowActionClick} />
 						<VerticalBar.Close onClick={onClose} />
 					</VerticalBar.Actions>
 				</VerticalBar.Header>

packages/rocketchat-i18n/i18n/en.i18n.json

@@ -1684,6 +1684,7 @@
   "Exclude_pinned": "Exclude pinned messages",
   "Execute_Synchronization_Now": "Execute Synchronization Now",
   "Exit_Full_Screen": "Exit Full Screen",
+  "Expand": "Expand",
   "Experimental_Feature_Alert": "This is an experimental feature! Please be aware that it may change, break, or even be removed in the future without any notice.",
   "Expiration": "Expiration",
   "Expiration_(Days)": "Expiration (Days)",