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/src/Http/Controllers/RefundController.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Modules\Payment\Http\Controllers;
+
+use Illuminate\Http\JsonResponse;
+use Illuminate\Routing\Controller;
+use Illuminate\Support\Facades\Gate;
+use Modules\Booking\Models\Booking;
+use Modules\Payment\Actions\RefundBookingAction;
+use Modules\Payment\Http\Requests\RefundBookingRequest;
+use Modules\Payment\Http\Resources\RefundResource;
+
+class RefundController extends Controller
+{
+    public function __construct(
+        private RefundBookingAction $refundBookingAction,
+    ) {}
+
+    public function refund(RefundBookingRequest $request, Booking $booking): JsonResponse
+    {
+        Gate::authorize('refund', $booking);
+
+        $validated = $request->validated();
+
+        $refund = $this->refundBookingAction->handle(
+            $booking,
+            (string) $validated['amount'],
+            $validated['reason'],
+            $request->user()?->id,
+        );
+
+        return (new RefundResource($refund))
+            ->response()
+            ->setStatusCode(201);
+    }
+}