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/Http/Resources/PageResource.php

@@ -49,6 +49,8 @@ class PageResource extends JsonResource
 
             'category' => CategoryResource::make($this->whenLoaded('category')),
             'author' => UserResource::make($this->whenLoaded('author')),
+            'byline_member_id' => $this->byline_member_id,
+            'tag_ids' => $this->whenLoaded('tags', fn () => $this->tags->pluck('id')->values()),
 
             // Opt-in: `?with=translations` returns every language at once,
             // which is what a translation UI needs and a page renderer does not.