Tag blog posts and sign them with a member

Tags are named in every language and made from the page form; the byline is
the member who signs a post on the site. The public API sends both, filters
posts by tag and lists the tags in use.

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

app/Policies/TagPolicy.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Policies;
+
+/**
+ * Tags are kept by whoever keeps the categories: the same job, sorting the
+ * blog, with no separate permission nobody would remember to grant.
+ */
+class TagPolicy extends ResourcePolicy
+{
+    protected function resource(): string
+    {
+        return 'categories';
+    }
+}