Aggiunge copertina sponsor custom solo Premium Full, con override in wizard e slate sui nodi di streaming.

Permette upload da portale e app con ereditarietà partita→squadra→società, generazione MP4 via ffmpeg e distribuzione su home lab e nodi CPX per pause e assenza segnale.

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

backend/app/services/teams/entitlements.rb

@@ -35,6 +35,20 @@ module Teams
       active? && plan.phone_download_enabled?
     end
 
+    def can_use_custom_cover?
+      premium_full? && plan.custom_cover_enabled?
+    end
+
+    def assert_can_upload_cover!
+      unless can_use_custom_cover?
+        raise EntitlementError.new(
+          "La copertina sponsor personalizzata richiede Premium Full",
+          code: "premium_full_required",
+          billing_url: billing_url
+        )
+      end
+    end
+
     def max_staff_transmission
       plan.max_staff_transmission
     end
@@ -225,7 +239,8 @@ module Teams
         recording_retention_days: recording_retention_days,
         phone_download_enabled: phone_download_enabled?,
         youtube_enabled: youtube_enabled?,
-        youtube_mode: plan.youtube_mode
+        youtube_mode: plan.youtube_mode,
+        custom_cover_enabled: can_use_custom_cover?
       }
     end