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/invite_preview.dart

@@ -0,0 +1,28 @@
+class InvitePreview {
+  const InvitePreview({
+    required this.valid,
+    required this.email,
+    required this.teamName,
+    this.clubName,
+    this.teamId,
+    this.error,
+  });
+
+  final bool valid;
+  final String email;
+  final String teamName;
+  final String? clubName;
+  final String? teamId;
+  final String? error;
+
+  factory InvitePreview.fromJson(Map<String, dynamic> json) {
+    return InvitePreview(
+      valid: json['valid'] as bool? ?? false,
+      email: json['email'] as String? ?? '',
+      teamName: json['team_name'] as String? ?? '',
+      clubName: json['club_name'] as String?,
+      teamId: json['team_id'] as String?,
+      error: json['error'] as String?,
+    );
+  }
+}

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,
     );
   }
 }