Fix PCI Stripe e anteprima regia; checkout sempre hosted.

Blocca l'invio di numeri carta dall'API server, usa Checkout anche per i cambi piano e nasconde correttamente il placeholder video in regia.

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

backend/app/services/billing/stripe/customer_sync.rb

@@ -0,0 +1,41 @@
+module Billing
+  module Stripe
+    # Sincronizza solo dati di fatturazione (mai dati carta) sul Customer Stripe.
+    class CustomerSync
+      def self.call(club:, customer_id:)
+        new(club: club, customer_id: customer_id).call
+      end
+
+      def initialize(club:, customer_id:)
+        @club = club
+        @customer_id = customer_id
+      end
+
+      def call
+        return @customer_id if @customer_id.blank?
+
+        ::Stripe::Customer.update(@customer_id, customer_attributes)
+        @customer_id
+      end
+
+      private
+
+      def customer_attributes
+        attrs = {
+          name: @club.billing_legal_name.presence || @club.name,
+          email: @club.billing_email.presence,
+          metadata: { club_id: @club.id },
+          address: {
+            line1: @club.billing_address_line,
+            city: @club.billing_city,
+            state: @club.billing_province,
+            postal_code: @club.billing_postal_code,
+            country: @club.billing_country.presence || "IT"
+          }
+        }
+        attrs[:address] = nil if attrs[:address].values.all?(&:blank?)
+        attrs.compact
+      end
+    end
+  end
+end