Aggiunge i tornei con hub, pagina pubblica e tabellone per semifinali e finali.

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

backend/app/services/tournaments/grant_broadcast_access.rb

@@ -0,0 +1,21 @@
+module Tournaments
+  class GrantBroadcastAccess
+    def self.call(invitation:, user:)
+      new(invitation: invitation, user: user).call
+    end
+
+    def initialize(invitation:, user:)
+      @invitation = invitation
+      @user = user
+    end
+
+    def call
+      team = Tournaments::EnsureBroadcastTeam.call(@invitation.tournament)
+      membership = UserTeam.find_or_initialize_by(user: @user, team: team)
+      membership.role = "member" if membership.new_record?
+      membership.staff_kind = "transmission"
+      membership.save!
+      membership
+    end
+  end
+end