Aggiunge pagamento con bonifico e importo concordato per società.

Il piano si attiva solo dopo la conferma admin; Stripe resta a listino se non c'è un prezzo commerciale.

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

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

@@ -86,6 +86,24 @@ module Billing
           end
         end
 
+        def catalog_intervals(plan_slug:)
+          INTERVALS.select { |interval| AMOUNTS.dig(plan_slug.to_s, interval, :charge).present? }
+        end
+
+        def amount_cents(plan_slug:, interval:)
+          interval = normalize_interval(interval)
+          cents = charge_cents(plan_slug, interval)
+          raise ArgumentError, "Prezzo listino non disponibile per #{plan_slug} (#{interval})" if cents.blank?
+
+          cents
+        end
+
+        def format_interval_price(cents, interval)
+          return nil if cents.blank?
+
+          I18n.t("billing.prices.#{interval}", amount: format_eur(cents))
+        end
+
         private
 
         def charge_cents(plan_slug, interval)
@@ -96,12 +114,6 @@ module Billing
           AMOUNTS.dig(plan_slug.to_s, interval, :list)
         end
 
-        def format_interval_price(cents, interval)
-          return nil if cents.blank?
-
-          I18n.t("billing.prices.#{interval}", amount: format_eur(cents))
-        end
-
         def price_id_for(plan_slug, interval)
           case [plan_slug, interval]
           when %w[premium_light monthly]