fix: optimize ChatView to prevent excessive re-rendering when typing

- Properly memoized itemContent callback with stable dependencies
- Added memoization for lastModifiedMessage to prevent unnecessary recalculations
- Removed debug logging after confirming the fix works

This fixes the UI jittering issue that occurred when typing in the chat input
by preventing the groupedMessages and itemContent from being recalculated on
every keystroke.

webview-ui/src/components/chat/ChatRow.tsx

@@ -68,6 +68,7 @@ interface ChatRowContentProps extends Omit<ChatRowProps, "onHeightChange"> {}
 const ChatRow = memo(
 	(props: ChatRowProps) => {
 		const { isLast, onHeightChange, message } = props
+
 		// Store the previous height to compare with the current height
 		// This allows us to detect changes without causing re-renders
 		const prevHeightRef = useRef(0)

webview-ui/src/components/chat/ChatView.tsx

@@ -160,7 +160,9 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 		return getLatestTodo(messages)
 	}, [messages, currentTaskTodos])
 
-	const modifiedMessages = useMemo(() => combineApiRequests(combineCommandSequences(messages.slice(1))), [messages])
+	const modifiedMessages = useMemo(() => {
+		return combineApiRequests(combineCommandSequences(messages.slice(1)))
+	}, [messages])
 
 	// Has to be after api_req_finished are all reduced into api_req_started messages.
 	const apiMetrics = useMemo(() => getApiMetrics(modifiedMessages), [modifiedMessages])
@@ -1521,6 +1523,10 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 		userRespondedRef.current = true
 	}, [])
 
+	// Memoize the last modified message to prevent unnecessary re-renders
+	const lastModifiedMessage = useMemo(() => modifiedMessages.at(-1), [modifiedMessages])
+
+	// Properly memoized itemContent callback with stable dependencies
 	const itemContent = useCallback(
 		(index: number, messageOrGroup: ClineMessage | ClineMessage[]) => {
 			// browser session group
@@ -1529,7 +1535,7 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 					<BrowserSessionRow
 						messages={messageOrGroup}
 						isLast={index === groupedMessages.length - 1}
-						lastModifiedMessage={modifiedMessages.at(-1)}
+						lastModifiedMessage={lastModifiedMessage}
 						onHeightChange={handleRowHeightChange}
 						isStreaming={isStreaming}
 						isExpanded={(messageTs: number) => expandedRows[messageTs] ?? false}
@@ -1549,12 +1555,12 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 					key={messageOrGroup.ts}
 					message={messageOrGroup}
 					isExpanded={expandedRows[messageOrGroup.ts] || false}
-					onToggleExpand={toggleRowExpansion} // This was already stabilized
-					lastModifiedMessage={modifiedMessages.at(-1)} // Original direct access
-					isLast={index === groupedMessages.length - 1} // Original direct access
+					onToggleExpand={toggleRowExpansion}
+					lastModifiedMessage={lastModifiedMessage}
+					isLast={index === groupedMessages.length - 1}
 					onHeightChange={handleRowHeightChange}
 					isStreaming={isStreaming}
-					onSuggestionClick={handleSuggestionClickInRow} // This was already stabilized
+					onSuggestionClick={handleSuggestionClickInRow}
 					onBatchFileResponse={handleBatchFileResponse}
 					onFollowUpUnmount={handleFollowUpUnmount}
 					isFollowUpAnswered={messageOrGroup.ts === currentFollowUpTs}
@@ -1582,7 +1588,7 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 		[
 			expandedRows,
 			toggleRowExpansion,
-			modifiedMessages,
+			lastModifiedMessage, // Use the memoized value instead of recalculating
 			groupedMessages.length,
 			handleRowHeightChange,
 			isStreaming,