Complete Payment module: initiate/webhook/confirm/refund actions, Filament resources (T5.8-T5.13)

- InitiatePaymentAction + POST /api/v1/payments/{booking}/initiate
- Generic KBZ webhook (POST /api/v1/webhooks/{method}/{encryptBookingId?}),
  signature verification per KBZ's real callback spec, PaymentGatewayInterface::handleWebhook()
- ConfirmPaymentAction: idempotent confirmation, PaymentCompleted/PaymentFailed events,
  MarkBookingPaid listener
- RefundBookingAction + POST /api/v1/bookings/{booking}/refund: partial refunds validated
  against remaining balance, RefundProcessed event, MarkBookingRefunded listener
- CancelBookingAction now refunds confirmed bookings instead of rejecting; BookingPolicy::cancel
  requires process_refunds for confirmed bookings
- PaymentPlugin + PaymentResource/RefundResource Filament admin UI (read-only payments,
  refund list + Process action)
- Booking detail page now shows related payments
- Fix CACHE_STORE mismatch (database -> redis) so tagged route caching works
- CLAUDE.md: never run migrate:fresh/migrate:refresh/db:wipe on dev without being asked

app-modules/payment/tests/Feature/PaymentGatewayFactoryTest.php

@@ -30,6 +30,11 @@ class FakePaymentGateway implements PaymentGatewayInterface
     {
         throw new RuntimeException('not needed for this test');
     }
+
+    public function handleWebhook(array $payload): PaymentResultData
+    {
+        throw new RuntimeException('not needed for this test');
+    }
 }
 
 test('the factory resolves KbzMiniAppGateway for the KbzMiniApp method by default', function () {