Turn off alternate buffer mode by default. (#13623)

packages/cli/src/config/settingsSchema.ts

@@ -516,7 +516,7 @@ const SETTINGS_SCHEMA = {
         label: 'Use Alternate Screen Buffer',
         category: 'UI',
         requiresRestart: true,
-        default: true,
+        default: false,
         description:
           'Use an alternate screen buffer for the UI, preserving shell history.',
         showInDialog: true,

packages/cli/src/gemini.test.tsx

@@ -509,6 +509,7 @@ describe('startInteractiveUI', () => {
     merged: {
       ui: {
         hideWindowTitle: false,
+        useAlternateBuffer: true,
       },
     },
   } as LoadedSettings;

packages/cli/src/test-utils/render.tsx

@@ -176,7 +176,7 @@ export const renderWithProviders = (
     width,
     mouseEventsEnabled = false,
     config = configProxy as unknown as Config,
-    useAlternateBuffer,
+    useAlternateBuffer = true,
     uiActions,
   }: {
     shellFocus?: boolean;

packages/cli/src/ui/hooks/useAlternateBuffer.ts

@@ -8,7 +8,7 @@ import { useSettings } from '../contexts/SettingsContext.js';
 import type { LoadedSettings } from '../../config/settings.js';
 
 export const isAlternateBufferEnabled = (settings: LoadedSettings): boolean =>
-  settings.merged.ui?.useAlternateBuffer !== false;
+  settings.merged.ui?.useAlternateBuffer === true;
 
 export const useAlternateBuffer = (): boolean => {
   const settings = useSettings();