fix(startup): show --model flag override on startup screen (#898)

The startup screen was only reading model from env vars and settings,
ignoring the --model CLI flag since it's parsed by Commander.js after
the banner prints. Now eagerly parses --model from argv before rendering
so the displayed model matches what the session will actually use.

src/entrypoints/cli.tsx

@@ -134,9 +134,13 @@ async function main(): Promise<void> {
 
   await validateProviderEnvForStartupOrExit()
 
+  // Parse --model early so the startup screen can display the override
+  const { eagerParseCliFlag } = await import('../utils/cliArgs.js')
+  const earlyModelFlag = eagerParseCliFlag('--model')
+
   // Print the gradient startup screen before the Ink UI loads
   const { printStartupScreen } = await import('../components/StartupScreen.js')
-  printStartupScreen()
+  printStartupScreen(earlyModelFlag)
 
   // For all other paths, load the startup profiler
   const {