feat: Add startup profiler to measure and record application initialization phases. (#13638)

packages/cli/src/ui/AppContainer.tsx

@@ -58,6 +58,7 @@ import {
   enableMouseEvents,
   disableLineWrapping,
   shouldEnterAlternateScreen,
+  startupProfiler,
 } from '@google/gemini-cli-core';
 import { validateAuthMethod } from '../config/auth.js';
 import process from 'node:process';
@@ -282,6 +283,7 @@ export const AppContainer = (props: AppContainerProps) => {
       // handled by the global catch.
       await config.initialize();
       setConfigInitialized(true);
+      startupProfiler.flush(config);
     })();
     registerCleanup(async () => {
       // Turn off mouse scroll.