Billing upgrade/downgrade, inviti in app e diretta YouTube da mobile.

Upgrade Stripe con addebito immediato; downgrade programmato a fine periodo.
UX billing più sobria con box info; icone piani. API inviti e OAuth YouTube
per staff trasmissione; deep link join; scelta partita programmata o nuova.

Co-authored-by: Cursor <cursoragent@cursor.com>

mobile/lib/shared/models/team.dart

@@ -29,6 +29,7 @@ class Team {
     this.staffRole,
     this.canStream = true,
     this.youtubeMode,
+    this.canConnectYoutube = false,
   });
 
   final String id;
@@ -60,6 +61,7 @@ class Team {
   final bool phoneDownloadEnabled;
   final bool youtubeEnabled;
   final String? youtubeMode;
+  final bool canConnectYoutube;
 
   bool get canUseYoutube => youtubeEnabled && (premiumFull || youtubeMode == 'matchlivetv_light');
 
@@ -105,6 +107,7 @@ class Team {
       phoneDownloadEnabled: json['phone_download_enabled'] as bool? ?? false,
       youtubeEnabled: json['youtube_enabled'] as bool? ?? false,
       youtubeMode: json['youtube_mode'] as String?,
+      canConnectYoutube: json['can_connect_youtube'] as bool? ?? false,
     );
   }
 }