Fix checkout Stripe: ricrea customer se ID test su ambiente live.

Evita errore «No such customer» dopo passaggio da sk_test a sk_live.

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

backend/spec/services/billing/stripe/ensure_customer_spec.rb

@@ -0,0 +1,29 @@
+require "rails_helper"
+
+RSpec.describe Billing::Stripe::EnsureCustomer do
+  let(:user) { User.create!(email: "ensure@test.it", name: "U", password: "password123", role: "coach") }
+  let(:club) do
+    Club.create!(name: "Ensure Club", sport: "volleyball", primary_color: "#e53935", secondary_color: "#ffffff")
+  end
+
+  before do
+    load Rails.root.join("db/seeds/plans.rb")
+    Billing::AssignPlan.call(club: club, plan_slug: "free")
+    club.subscription.update!(stripe_customer_id: "cus_stale_test_mode")
+  end
+
+  it "ricrea il customer se l'id salvato non esiste su Stripe" do
+    err = ::Stripe::InvalidRequestError.new("No such customer", 404, code: "resource_missing")
+    allow(Stripe::Customer).to receive(:retrieve).with("cus_stale_test_mode").and_raise(err)
+    allow(Stripe::Customer).to receive(:create).and_return(
+      double(id: "cus_live_new", email: user.email)
+    )
+    allow(Stripe::Customer).to receive(:update)
+
+    id = described_class.call(club: club, user: user)
+
+    expect(id).to eq("cus_live_new")
+    expect(club.subscription.reload.stripe_customer_id).to eq("cus_live_new")
+    expect(club.subscription.stripe_subscription_id).to be_nil
+  end
+end