feat: implement Hetzner deletion failure notification system with email and messaging support

resources/views/emails/hetzner-deletion-failed.blade.php

@@ -0,0 +1,13 @@
+<x-emails.layout>
+Failed to delete Hetzner server #{{ $hetznerServerId }} from Hetzner Cloud.
+
+Error:
+<pre>
+{{ $errorMessage }}
+</pre>
+
+The server has been removed from Coolify, but may still exist in your Hetzner Cloud account.
+
+Please check your Hetzner Cloud console and manually delete the server if needed to avoid ongoing charges.
+
+</x-emails.layout>