feat: add Weeztix OAuth, coupon codes, and Mailwizz mapping

Implement Weeztix integration per documentation: database config and
subscriber coupon_code, OAuth redirect/callback, admin setup UI with
company/coupon selection via AJAX, synchronous coupon creation on public
subscribe with duplicate and rate-limit handling, Mailwizz field mapping
for coupon codes, subscriber table and CSV export, and connection hint
on the pages list.

Made-with: Cursor

app/Http/Requests/Admin/UpdateMailwizzConfigRequest.php

@@ -42,6 +42,7 @@ class UpdateMailwizzConfigRequest extends FormRequest
             'field_first_name' => ['required', 'string', 'max:255'],
             'field_last_name' => ['required', 'string', 'max:255'],
             'field_phone' => ['nullable', 'string', 'max:255'],
+            'field_coupon_code' => ['nullable', 'string', 'max:255'],
             'tag_field' => ['required', 'string', 'max:255'],
             'tag_value' => ['required', 'string', 'max:255'],
         ];

app/Http/Requests/Admin/UpdateWeeztixConfigRequest.php

@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Requests\Admin;
+
+use App\Models\PreregistrationPage;
+use Illuminate\Contracts\Validation\ValidationRule;
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
+
+class UpdateWeeztixConfigRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        $page = $this->route('page');
+        if (! $page instanceof PreregistrationPage) {
+            return false;
+        }
+
+        return $this->user()?->can('update', $page) ?? false;
+    }
+
+    /**
+     * @return array<string, array<int, ValidationRule|string>>
+     */
+    public function rules(): array
+    {
+        /** @var PreregistrationPage $page */
+        $page = $this->route('page');
+
+        return [
+            'client_id' => [
+                'sometimes',
+                Rule::requiredIf(fn (): bool => $page->weeztixConfig === null),
+                'nullable',
+                'string',
+                'max:2048',
+            ],
+            'client_secret' => [
+                'sometimes',
+                Rule::requiredIf(fn (): bool => $page->weeztixConfig === null),
+                'nullable',
+                'string',
+                'max:2048',
+            ],
+            'company_guid' => ['nullable', 'string', 'max:255'],
+            'company_name' => ['nullable', 'string', 'max:255'],
+            'coupon_guid' => ['nullable', 'string', 'max:255'],
+            'coupon_name' => ['nullable', 'string', 'max:255'],
+            'code_prefix' => ['nullable', 'string', 'max:32'],
+            'usage_count' => ['nullable', 'integer', 'min:1', 'max:99999'],
+        ];
+    }
+}