Aggiunge abbonamenti omaggio admin per sponsor e promozioni.

Gli admin possono concedere o revocare Premium Light/Full senza Stripe;
il piano omaggio ha priorità sui webhook e la società vede un messaggio dedicato.

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

backend/spec/services/billing/admin_comped_subscription_spec.rb

@@ -0,0 +1,36 @@
+require "rails_helper"
+
+RSpec.describe Billing::AdminCompedSubscription do
+  let(:admin) { AdminAccount.create!(username: "ops", password: "secret123") }
+  let(:club) { Club.create!(name: "Sponsor FC", sport: "volleyball", primary_color: "#e53935", secondary_color: "#ffffff") }
+
+  before do
+    load Rails.root.join("db/seeds/plans.rb")
+    Billing::AssignPlan.call(club: club, plan_slug: "free")
+  end
+
+  it "concede premium full senza stripe" do
+    described_class.grant(
+      club: club,
+      plan_slug: "premium_full",
+      reason: "Sponsor stagione 2026",
+      admin: admin
+    )
+
+    sub = club.reload.subscription
+    expect(sub.plan.slug).to eq("premium_full")
+    expect(sub.admin_comped?).to be true
+    expect(sub.admin_comped_reason).to eq("Sponsor stagione 2026")
+    expect(sub.admin_comped_by).to eq(admin)
+  end
+
+  it "revoca omaggio e torna a free" do
+    described_class.grant(club: club, plan_slug: "premium_light", reason: "Promo", admin: admin)
+
+    described_class.revoke(club: club, admin: admin)
+
+    sub = club.reload.subscription
+    expect(sub.plan.slug).to eq("free")
+    expect(sub.admin_comped?).to be false
+  end
+end