feat(loyalty): give new balances their expiry

Every lot now gets its expiry when it is created (docs/prd-point-coin.md
F12, PC-502), where it used to never expire until note N4 was settled:

- EARN and an ADJUSTMENT that adds: ComputeExpiry of the organization's
  settings for that currency, from the moment received.
- EXCHANGE_IN: the sooner of the EnakCoin lot's expiry and when EnakPoint
  received now expire (F4).
- PAYMENT_REFUND: the expiry of the lot the EnakPoint came from, but at
  least seven days from the refund (N4, decided). A lot that never expired
  stays so.
- TRANSFER_IN: unchanged, exactly the sender's expiry.

Turning expiry on for a currency for the first time dates every lot of the
organization that still holds something and has no expiry, MIGRATION lots
included, in the same transaction as the setting: a full period from now
when ROLLING, the second fixed date on or after today when FIXED_DATE, so
no customer loses a balance soon after the rule is announced (N4,
decided). Turning it off leaves dated lots as they are. PUT
/marketing/loyalty-settings reports these as expiry_activations (currency,
lots, amount, expires_at); a dry run counts them without dating anything.

The earning processor now also reads the organization settings, and the
wallet admin processor takes the settings reader.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/processor/wallet_admin_processor.go

@@ -21,15 +21,16 @@ const walletDescriptionLimit = 255
 // WalletAdminProcessor serves the dashboard's view of one customer's wallet and the
 // manual adjustments an admin makes to it (docs/prd-point-coin.md F7).
 type WalletAdminProcessor struct {
-	admin  repository.WalletAdminRepository
-	query  repository.WalletQueryRepository
-	wallet *WalletProcessor
-	tx     TxRunner
-	now    func() time.Time
+	admin    repository.WalletAdminRepository
+	query    repository.WalletQueryRepository
+	wallet   *WalletProcessor
+	settings organizationSettingsReader
+	tx       TxRunner
+	now      func() time.Time
 }
 
-func NewWalletAdminProcessor(admin repository.WalletAdminRepository, query repository.WalletQueryRepository, wallet *WalletProcessor, tx TxRunner) *WalletAdminProcessor {
-	return &WalletAdminProcessor{admin: admin, query: query, wallet: wallet, tx: tx, now: time.Now}
+func NewWalletAdminProcessor(admin repository.WalletAdminRepository, query repository.WalletQueryRepository, wallet *WalletProcessor, settings organizationSettingsReader, tx TxRunner) *WalletAdminProcessor {
+	return &WalletAdminProcessor{admin: admin, query: query, wallet: wallet, settings: settings, tx: tx, now: time.Now}
 }
 
 // GetCustomerWallet returns the customer's balances, lots and a page of history.
@@ -126,13 +127,20 @@ func (p *WalletAdminProcessor) Adjust(ctx context.Context, organizationID, admin
 		if _, err := p.admin.GetCustomer(ctx, organizationID, customerID); err != nil {
 			return err
 		}
-		var err error
-		if in.Amount > 0 {
-			// Adjustments never expire until expiry is decided (F12, note N4).
-			res, err = p.wallet.Credit(ctx, WalletCreditInput{WalletEntry: entry})
-		} else {
+		if in.Amount < 0 {
+			var err error
 			res, err = p.wallet.Debit(ctx, WalletDebitInput{WalletEntry: entry})
+			return err
 		}
+		// An adjustment that adds is a new balance, and expires like one (F7, F12).
+		settings, err := p.settings.Organization(ctx, organizationID)
+		if err != nil {
+			return err
+		}
+		res, err = p.wallet.Credit(ctx, WalletCreditInput{
+			WalletEntry: entry,
+			Lots:        []WalletLotInput{{Amount: entry.Amount, ExpiresAt: ComputeExpiry(ExpirySettings(settings, in.Currency), p.now())}},
+		})
 		return err
 	})
 	if err != nil {