Club come entità principale, branding e fix infrastruttura streaming.

Introduce clubs con abbonamento, branding Active Storage e flusso registrazione società; corregge healthcheck MediaMTX (immagine distroless) e allinea dominio produzione matchlivetv.it.

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

backend/app/controllers/public/registrations_controller.rb

@@ -1,7 +1,7 @@
 module Public
   class RegistrationsController < WebBaseController
     def new
-      redirect_to public_team_dashboard_path(current_user.teams.first) if logged_in? && current_user.teams.any?
+      redirect_to public_club_path(current_user.primary_club) if logged_in? && current_user.primary_club
       @user = User.new
     end
 
@@ -23,7 +23,7 @@ module Public
             return redirect_to public_team_dashboard_path(invitation.team), notice: "Benvenuto nella squadra!"
           end
         end
-        redirect_to new_public_team_path, notice: "Account creato. Ora crea la tua squadra."
+        redirect_to public_new_club_path, notice: "Account creato. Ora registra la tua società."
       else
         flash.now[:alert] = @user.errors.full_messages.join(", ")
         render :new, status: :unprocessable_entity