feat(ui): add /settings command and UI panel (#4738)

Co-authored-by: Jacob Richman <jacob314@gmail.com>

packages/cli/src/ui/App.tsx

@@ -93,6 +93,8 @@ import ansiEscapes from 'ansi-escapes';
 import { OverflowProvider } from './contexts/OverflowContext.js';
 import { ShowMoreLines } from './components/ShowMoreLines.js';
 import { PrivacyNotice } from './privacy/PrivacyNotice.js';
+import { useSettingsCommand } from './hooks/useSettingsCommand.js';
+import { SettingsDialog } from './components/SettingsDialog.js';
 import { setUpdateHandler } from '../utils/handleAutoUpdate.js';
 import { appEvents, AppEvent } from '../utils/events.js';
 import { isNarrowWidth } from './utils/isNarrowWidth.js';
@@ -247,6 +249,9 @@ const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
     handleThemeHighlight,
   } = useThemeCommand(settings, setThemeError, addItem);
 
+  const { isSettingsDialogOpen, openSettingsDialog, closeSettingsDialog } =
+    useSettingsCommand();
+
   const { isFolderTrustDialogOpen, handleFolderTrustSelect } =
     useFolderTrust(settings);
 
@@ -510,6 +515,7 @@ const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
     toggleCorgiMode,
     setQuittingMessages,
     openPrivacyNotice,
+    openSettingsDialog,
     toggleVimEnabled,
     setIsProcessing,
     setGeminiMdFileCount,
@@ -975,6 +981,14 @@ const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
                 terminalWidth={mainAreaWidth}
               />
             </Box>
+          ) : isSettingsDialogOpen ? (
+            <Box flexDirection="column">
+              <SettingsDialog
+                settings={settings}
+                onSelect={() => closeSettingsDialog()}
+                onRestartRequest={() => process.exit(0)}
+              />
+            </Box>
           ) : isAuthenticating ? (
             <>
               <AuthInProgress
@@ -1164,7 +1178,7 @@ const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
             errorCount={errorCount}
             showErrorDetails={showErrorDetails}
             showMemoryUsage={
-              config.getDebugMode() || config.getShowMemoryUsage()
+              config.getDebugMode() || settings.merged.showMemoryUsage || false
             }
             promptTokenCount={sessionStats.lastPromptTokenCount}
             nightly={nightly}