1.2.0

• New setting private_payment ("Private payments", default off). When on and the environment is
  live, a native intent is created with private_payment: 'hinkal', so the hosted checkout also
  offers "Pay privately with Hinkal". Sponsored (no-ETH) intents, subscriptions and the test network
  never carry it (P2Flux refuses it there).
• A verified settlement whose accounting.refundable is false (paid through a privacy service)
  stores _p2flux_refundable = no and adds an order note on how to refund manually.