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/Support/CrmPrefillCodec.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Support;
+
+final class CrmPrefillCodec
+{
+    public static function encode(array $payload): string
+    {
+        return rtrim(strtr(base64_encode(json_encode($payload, JSON_THROW_ON_ERROR)), '+/', '-_'), '=');
+    }
+
+    /** @return array<string, mixed>|null */
+    public static function decode(?string $token): ?array
+    {
+        if (! is_string($token) || $token === '') {
+            return null;
+        }
+
+        $padded = $token.str_repeat('=', (4 - strlen($token) % 4) % 4);
+        $json = base64_decode(strtr($padded, '-_', '+/'), true);
+
+        if ($json === false) {
+            return null;
+        }
+
+        try {
+            $data = json_decode($json, true, 512, JSON_THROW_ON_ERROR);
+        } catch (\JsonException) {
+            return null;
+        }
+
+        return is_array($data) ? $data : null;
+    }
+}