Warn about calls closing and content coming off the site

A dashboard widget lists what expires in the next two weeks, and a daily
command reminds whoever edits it a week and a day ahead.

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

config/site.php

@@ -165,4 +165,17 @@ return [
         // the notification bell is always on, and mail needs a working mailer.
         'notify_by_mail' => (bool) env('SITE_SUBMISSION_MAIL', false),
     ],
+
+    /*
+    |--------------------------------------------------------------------------
+    | Expiry reminders
+    |--------------------------------------------------------------------------
+    |
+    | Days ahead of a call closing, or of published content coming off the
+    | site, on which `content:expiring` tells the people who edit it.
+    |
+    */
+
+    'expiry_reminders' => [7, 1],
+
 ];