feat(ads): wire real AdMob ids (Phase 5 finalize)

Replaces the TODO_REAL_* ad-unit placeholders with the owner's real AdMob
console ids (publisher pub-5605900229781491) and the native AdMob app ids
(iOS ~8397095848, Android ~8257495040) in place of the Google sample ids.
Debug builds still serve Google test ads via kDebugMode; release builds now
use the real units.

ios/Runner/Info.plist

@@ -46,7 +46,7 @@
 	<key>UIApplicationSupportsIndirectInputEvents</key>
 	<true/>
 	<key>GADApplicationIdentifier</key>
-	<string>ca-app-pub-3940256099942544~1458002511</string>
+	<string>ca-app-pub-5605900229781491~8397095848</string>
 	<key>NSUserTrackingUsageDescription</key>
 	<string>We use this to show ads that are more relevant to you. You can play fully either way.</string>
 	<key>SKAdNetworkItems</key>