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/PaymentPlugin.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Modules\Payment;
+
+use Filament\Contracts\Plugin;
+use Filament\Panel;
+
+class PaymentPlugin implements Plugin
+{
+    public function getId(): string
+    {
+        return 'payment';
+    }
+
+    public function register(Panel $panel): void
+    {
+        $panel
+            ->discoverResources(
+                in: __DIR__.'/Filament/Resources',
+                for: 'Modules\Payment\Filament\Resources',
+            )
+            ->discoverPages(
+                in: __DIR__.'/Filament/Pages',
+                for: 'Modules\Payment\Filament\Pages',
+            )
+            ->discoverWidgets(
+                in: __DIR__.'/Filament/Widgets',
+                for: 'Modules\Payment\Filament\Widgets',
+            );
+    }
+
+    public function boot(Panel $panel): void {}
+
+    public static function make(): static
+    {
+        return app(static::class);
+    }
+}