test(app): align startup splash and host-page tests with desktop settings IPC

- Add testID="startup-splash" to the simplified splash screen so e2e helpers
  can detect desktop daemon bootstrap without depending on removed copy.
- Update startup-dsl helper to assert the testID instead of the deprecated
  "Starting local server..." text.
- Replace the obsolete localStorage write for manageBuiltInDaemon in the
  local-daemon sidebar test with a get_desktop_settings IPC mock so the
  desktop bridge surfaces the seeded host without triggering bootstrap.

packages/app/src/screens/startup-splash-screen.tsx

@@ -392,7 +392,7 @@ export function StartupSplashScreen({ bootstrapState }: StartupSplashScreenProps
 
   if (!isError) {
     return (
-      <View style={styles.container}>
+      <View testID="startup-splash" style={styles.container}>
         <TitlebarDragRegion />
         <LogoShimmer />
       </View>