Billing: fatture manuali, profilo obbligatorio e piani Stripe mensile/annuale.

Rimuove link al portale Stripe in area cliente, aggiunge flusso admin per PDF
fattura e email, blocca checkout senza dati di fatturazione, allinea prezzi
a €4,90/€39,90 e €9,90/€69,90, locale italiano e documentazione deploy.

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

backend/app/services/billing/issue_invoice.rb

@@ -0,0 +1,47 @@
+module Billing
+  class IssueInvoice
+    class Error < StandardError; end
+
+    def self.call(invoice:, pdf: nil)
+      new(invoice: invoice, pdf: pdf).call
+    end
+
+    def initialize(invoice:, pdf: nil)
+      @invoice = invoice
+      @pdf = pdf
+    end
+
+    def call
+      raise Error, "Carica il file PDF della fattura" if @pdf.blank? && !@invoice.pdf.attached?
+
+      attach_pdf!(@pdf) if @pdf.present?
+      raise Error, "PDF mancante" unless @invoice.pdf.attached?
+
+      recipient = @invoice.club.billing_email.presence
+      raise Error, "Email di fatturazione non configurata per la società" if recipient.blank?
+
+      @invoice.update!(status: "issued")
+
+      Billing::InvoiceMailer.with(invoice: @invoice).invoice_pdf.deliver_now
+      @invoice.update!(status: "sent", emailed_at: Time.current)
+
+      @invoice
+    end
+
+    def attach_pdf!(upload)
+      if upload.respond_to?(:tempfile)
+        @invoice.pdf.attach(
+          io: upload.tempfile,
+          filename: upload.original_filename,
+          content_type: upload.content_type.presence || "application/pdf"
+        )
+      elsif upload.is_a?(Hash)
+        @invoice.pdf.attach(**upload)
+      elsif upload.is_a?(StringIO)
+        @invoice.pdf.attach(io: upload, filename: "fattura.pdf", content_type: "application/pdf")
+      else
+        @invoice.pdf.attach(upload)
+      end
+    end
+  end
+end