Replace the vanilla Flutter splash with the OOTT wordmark (Barlow
Condensed Bold) on the Gruvbox-dark background, matching the in-app
AppBar badge. Generated via flutter_native_splash, covering legacy
Android, the Android 12+ SplashScreen API, and iOS (light + dark).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
