Send signed outgoing webhooks

Fed by the records themselves, delivered only to public HTTPS addresses
checked at every attempt, retried, and switched off after repeated failures.
A submitter's details travel only to webhooks that opted into them.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Policies/WebhookPolicy.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Policies;
+
+class WebhookPolicy extends ResourcePolicy
+{
+    protected function resource(): string
+    {
+        return 'webhooks';
+    }
+}