v0.1.0 of admob_kit_x

High-level AdMob integration for Flutter. Banner, interstitial, rewarded, and app-open ads with UMP consent flow, automatic test/production ID switching, retry with exponential backoff, and frequency [...] Changelog excerpt: - Initial release. - AdManager with initialization, lifecycle management, and event streaming. - BannerAdWidget with adaptive banner support. - InterstitialController with frequency capping and auto-preload. - RewardedController with reward callback. - AppOpenController with cold-start skip option. - ConsentManager for UMP (GDPR/CCPA) consent flow. - Automatic test/production ad ID switching via kDebugMode. - Exponential backoff retry on load failures. - FakeAdManager for easy testing without real ads.