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_exchange_processor_test.go

@@ -332,3 +332,23 @@ func TestWalletExchange_RequiresAnIdempotencyKey(t *testing.T) {
 	assert.ErrorIs(t, err, ErrWalletMoveRejected)
 	assert.Empty(t, e.pins.actions)
 }
+
+// F4: EnakPoint from an exchange expire at the sooner of the EnakCoin lot's expiry and
+// when EnakPoint received now would expire.
+func TestWalletExchange_CappedByThePointExpiry(t *testing.T) {
+	e := newWalletMoveEnv(t)
+	e.now = wib(2026, 6, 1, 10, 0)
+	e.settings.PointExpiry = rolling(30, "DAY", false)
+	c := e.member("Budi", "081234561234")
+	soon, later := e.at(24*time.Hour), e.at(90*24*time.Hour)
+	e.earnCoins(t, c, 10, soon)
+	e.earnCoins(t, c, 10, later)
+	e.earnCoins(t, c, 10, nil)
+
+	res, err := e.exchanges().Exchange(e.ctx, c, 30, "482913", "key-1", models.CustomerPinRequestInfo{})
+	require.NoError(t, err)
+	require.Len(t, res.Lots, 3)
+	assert.Equal(t, soon, res.Lots[0].ExpiresAt, "the EnakCoin lot expires first")
+	assert.Equal(t, "2026-07-01", expiryDay(t, res.Lots[1].ExpiresAt), "30 days of EnakPoint come first")
+	assert.Equal(t, "2026-07-01", expiryDay(t, res.Lots[2].ExpiresAt), "a lot that never expired gets the EnakPoint expiry")
+}