Add Ladill POS v1 — register, Pay checkout, and commerce links.

Staff-facing counter register at pos.ladill.com with catalog cart, cash and
MoMo/card checkout via Ladill Pay, CRM timeline/import, invoice prefill, and
Merchant catalog import.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Services/Pay/PayClient.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace App\Services\Pay;
+
+use Illuminate\Support\Facades\Http;
+
+/**
+ * Client for the platform Ladill Pay HTTP API — checkout and settlement for
+ * merchant↔buyer money. Paystack is the processor today; settlement lands in
+ * the one UserWallet via Platform Billing.
+ */
+class PayClient
+{
+    private function base(): string
+    {
+        return rtrim((string) config('pay.api_url'), '/');
+    }
+
+    private function token(): string
+    {
+        return (string) (config('pay.api_key') ?? '');
+    }
+
+    /** @param array<string,mixed> $payload */
+    public function createCheckout(array $payload): array
+    {
+        $res = Http::withToken($this->token())->acceptJson()->timeout(15)->post($this->base().'/checkouts', $payload);
+        $res->throw();
+
+        return (array) $res->json();
+    }
+
+    public function verify(string $reference): array
+    {
+        $res = Http::withToken($this->token())->acceptJson()->timeout(15)->post($this->base().'/checkouts/verify', [
+            'reference' => $reference,
+        ]);
+        $res->throw();
+
+        return (array) $res->json();
+    }
+
+    public function show(string $reference): array
+    {
+        $res = Http::withToken($this->token())->acceptJson()->timeout(10)->get($this->base().'/orders/'.$reference);
+        $res->throw();
+
+        return (array) $res->json();
+    }
+}