update email template

app/Integrations/Whmcs/Support/SlugUniquifier.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace App\Integrations\Whmcs\Support;
+
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Str;
+
+/** Slugifies a candidate and appends -N until it's unique in the given column, excluding the row's own legacy_id. */
+class SlugUniquifier
+{
+    public function unique(string $table, string $column, string $candidate, int $legacyId): string
+    {
+        $base = Str::slug($candidate) ?: 'item';
+        $slug = $base;
+        $suffix = 1;
+
+        while (DB::table($table)->where($column, $slug)->where('legacy_id', '!=', $legacyId)->exists()) {
+            $slug = "{$base}-" . ++$suffix;
+        }
+
+        return $slug;
+    }
+}