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

config/weeztix.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+
+    /*
+    |--------------------------------------------------------------------------
+    | OAuth / token host (authorization code + refresh)
+    |--------------------------------------------------------------------------
+    |
+    | Defaults match the integration spec (Open Ticket auth). Token requests
+    | use {auth_base_url}/tokens; authorize URL is {auth_base_url}/tokens/authorize
+    | when using the same host layout as Weeztix/Open Ticket.
+    |
+    */
+
+    'auth_base_url' => rtrim((string) env('WEEZTIX_AUTH_BASE_URL', 'https://auth.openticket.tech'), '/'),
+
+    /*
+    |--------------------------------------------------------------------------
+    | Weeztix API base URL
+    |--------------------------------------------------------------------------
+    */
+
+    'api_base_url' => rtrim((string) env('WEEZTIX_API_BASE_URL', 'https://api.weeztix.com'), '/'),
+
+    /*
+    |--------------------------------------------------------------------------
+    | Current user profile (token validity + company hints)
+    |--------------------------------------------------------------------------
+    |
+    | Documented at https://docs.weeztix.com/docs/introduction/issue-request/
+    | Uses auth.weeztix.com by default; override if your token issuer uses another host.
+    |
+    */
+
+    'user_profile_url' => (string) env('WEEZTIX_USER_PROFILE_URL', 'https://auth.weeztix.com/users/me'),
+
+];