Admin fatturazione: coda pagamenti senza PDF e upload diretto.

Lista globale dei pagamenti da fatturare con dati intestazione, caricamento
PDF per riga che crea la fattura e invia email; rimuove il flusso bozza manuale.

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

backend/app/services/billing/attach_payment_invoice.rb

@@ -0,0 +1,37 @@
+module Billing
+  class AttachPaymentInvoice
+    class Error < StandardError; end
+
+    def self.call(payment:, pdf:)
+      new(payment: payment, pdf: pdf).call
+    end
+
+    def initialize(payment:, pdf:)
+      @payment = payment
+      @pdf = pdf
+    end
+
+    def call
+      raise Error, "Seleziona un file PDF" if @pdf.blank?
+      raise Error, "Pagamento non valido" unless @payment.status == "paid"
+
+      club = @payment.club
+      invoice = @payment.invoice || build_invoice!(club)
+      IssueInvoice.call(invoice: invoice, pdf: @pdf)
+    end
+
+    private
+
+    def build_invoice!(club)
+      club.billing_invoices.create!(
+        number: InvoiceNumber.next_for(club),
+        issued_on: @payment.paid_at&.to_date || Date.current,
+        amount_cents: @payment.amount_cents,
+        currency: @payment.currency.presence || "eur",
+        status: "draft",
+        source: "manual",
+        billing_payment: @payment
+      )
+    end
+  end
+end