Wire LadillLink through QrCode model and remaining QR surfaces.

Public URLs, encoded payloads, slug preview, payment callbacks, and asset paths now use ladl.link instead of ladill.com/q/*.

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

app/Support/LadillLink.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Support;
+
+/**
+ * Canonical short-link URLs for the Ladill platform (ladl.link).
+ */
+final class LadillLink
+{
+    public static function baseUrl(): string
+    {
+        $domain = (string) config('link.public_domain', 'ladl.link');
+
+        return 'https://'.$domain;
+    }
+
+    public static function url(string $slug): string
+    {
+        return rtrim(self::baseUrl(), '/').'/'.ltrim($slug, '/');
+    }
+
+    public static function path(string $slug, string $suffix): string
+    {
+        return self::url($slug).'/'.ltrim($suffix, '/');
+    }
+}