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/models/club_billing_profile_spec.rb

@@ -7,11 +7,14 @@ RSpec.describe ClubBillingProfile do
       sport: "volleyball",
       primary_color: "#e53935",
       secondary_color: "#ffffff",
+      billing_entity_type: "company",
       billing_legal_name: "ASD Test",
       billing_email: "billing@test.it",
       billing_address_line: "Via Roma 1",
       billing_city: "Milano",
+      billing_province: "MI",
       billing_postal_code: "20100",
+      billing_country: "IT",
       billing_vat_number: "12345678901",
       billing_recipient_code: "ABCDEFG"
     )
@@ -26,4 +29,16 @@ RSpec.describe ClubBillingProfile do
     club.billing_pec = nil
     expect(club.billing_profile_complete?).to be false
   end
+
+  it "requires P.IVA for companies" do
+    club.billing_vat_number = nil
+    expect(club.billing_profile_complete?).to be false
+    expect(club.billing_profile_errors).to include("Partita IVA")
+  end
+
+  it "requires Codice Fiscale for individuals" do
+    club.update!(billing_entity_type: "individual", billing_vat_number: nil, billing_fiscal_code: nil)
+    club.billing_fiscal_code = "RSSMRA80A01H501U"
+    expect(club.billing_profile_complete?).to be true
+  end
 end