Send a webhook for every change a person makes to a record

Events are {resource}.created, .updated, .deleted and .restored for content,
the inbox, redirects, repositories and media, taken from the audit log so the
two agree on what happened. Subscriptions take wildcards. Users, tokens,
webhooks and settings are never sent, nor what the application does by
itself; the inbox's own words only with personal data enabled.

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

lang/en/rules.php

@@ -44,6 +44,10 @@ return [
         'too_many' => 'At most :max rows per import.',
     ],
 
+    'webhooks' => [
+        'event' => '":event" is not an event that can be subscribed to.',
+    ],
+
     'tokens' => [
         'ability' => '":ability" is not a permission you hold, so a token of yours cannot hold it.',
         'machine' => 'Tokens are managed by a person, not by another token.',