Optimize VirtualizedList

Checkpoint optimizing virtualized list

Fixes for fallback rendering where terminalBuffer=false
Change terminalBuffer false back to the default while we fix performance
with very large chats.

Checkpoint changes to virtualized list.

Fix virtualized list

NO commit

Update ink version.

Fix UI snapshot mismatch in MainContent tests and VirtualizedList computation

Checkpoint.

packages/cli/src/ui/components/MainContent.tsx

@@ -22,6 +22,7 @@ import { MAX_GEMINI_MESSAGE_LINES } from '../constants.js';
 import { useConfirmingTool } from '../hooks/useConfirmingTool.js';
 import { ToolConfirmationQueue } from './ToolConfirmationQueue.js';
 import { appEvents, AppEvent } from '../../utils/events.js';
+import { useInputState } from '../contexts/InputContext.js';
 
 const MemoizedHistoryItemDisplay = memo(HistoryItemDisplay);
 const MemoizedAppHeader = memo(AppHeader);
@@ -37,6 +38,7 @@ export const MainContent = () => {
   const config = useConfig();
   const useTerminalBuffer = config.getUseTerminalBuffer();
   const isAlternateBuffer = config.getUseAlternateBuffer();
+  const { copyModeEnabled } = useInputState();
 
   const confirmingTool = useConfirmingTool();
   const showConfirmationQueue = confirmingTool !== null;
@@ -234,7 +236,7 @@ export const MainContent = () => {
     [showHeaderDetails, version, pendingItems],
   );
 
-  const estimatedItemHeight = useCallback(() => 100, []);
+  const estimatedItemHeight = useCallback(() => 10, []);
 
   const keyExtractor = useCallback(
     (item: (typeof virtualizedData)[number], _index: number) => {
@@ -271,7 +273,7 @@ export const MainContent = () => {
           renderStatic={useTerminalBuffer}
           isStaticItem={useTerminalBuffer ? isStaticItem : undefined}
           overflowToBackbuffer={useTerminalBuffer && !isAlternateBuffer}
-          scrollbar={mouseMode}
+          scrollbar={mouseMode && !copyModeEnabled}
         />
         // TODO(jacobr): consider adding stableScrollback={!config.getUseAlternateBuffer()}
         // as that will reduce the # of cases where we will have to clear the
@@ -295,6 +297,7 @@ export const MainContent = () => {
     isStaticItem,
     mouseMode,
     isAlternateBuffer,
+    copyModeEnabled,
   ]);
 
   if (!uiState.isConfigInitialized) {