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/spec/services/billing/stripe/finalize_subscription_spec.rb

@@ -0,0 +1,54 @@
+require "rails_helper"
+
+RSpec.describe Billing::Stripe::FinalizeSubscription do
+  let(:club) do
+    Club.create!(
+      name: "Fin Club", sport: "volleyball",
+      primary_color: "#e53935", secondary_color: "#ffffff"
+    )
+  end
+
+  before { load Rails.root.join("db/seeds/plans.rb") }
+
+  it "passa a free quando il periodo è scaduto e la disdetta era programmata" do
+    Billing::AssignPlan.call(
+      club: club,
+      plan_slug: "premium_light",
+      status: "active",
+      stripe_attrs: {
+        stripe_subscription_id: "sub_fin",
+        cancel_at_period_end: true,
+        current_period_end: 1.day.ago
+      }
+    )
+    stripe_sub = double(
+      id: "sub_fin",
+      status: "active",
+      cancel_at_period_end: true
+    )
+    allow(Stripe::Subscription).to receive(:retrieve).with("sub_fin").and_return(stripe_sub)
+    allow(Billing::Stripe::SubscriptionPeriod).to receive(:times).and_return([2.months.ago, 1.day.ago])
+
+    expect(described_class.call(club: club)).to be true
+    expect(club.reload.subscription.plan.slug).to eq("free")
+    expect(club.subscription.stripe_subscription_id).to be_nil
+  end
+
+  it "non cambia piano se il periodo non è ancora scaduto" do
+    Billing::AssignPlan.call(
+      club: club,
+      plan_slug: "premium_light",
+      status: "active",
+      stripe_attrs: {
+        stripe_subscription_id: "sub_ok",
+        cancel_at_period_end: true,
+        current_period_end: 1.month.from_now
+      }
+    )
+    stripe_sub = double(id: "sub_ok", status: "active", cancel_at_period_end: true)
+    allow(Stripe::Subscription).to receive(:retrieve).and_return(stripe_sub)
+
+    expect(described_class.call(club: club)).to be false
+    expect(club.reload.subscription.plan.slug).to eq("premium_light")
+  end
+end