Add per-app AP social UI for blog, market, and events

Lightweight social pages (search, follow/unfollow, followers, following,
actor timeline) auto-registered for AP-enabled apps via shared blueprint.
Federation keeps the full social hub. Followers scoped per app_domain;
post cards show "View on Hub" link instead of interaction buttons.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/browser/templates/social/following.html

@@ -0,0 +1,13 @@
+{% extends "_types/social_lite/index.html" %}
+
+{% block title %}Following — Rose Ash{% endblock %}
+
+{% block social_content %}
+<h1 class="text-2xl font-bold mb-6">Following <span class="text-stone-400 font-normal">({{ total }})</span></h1>
+
+<div id="actor-list">
+  {% set list_type = "following" %}
+  {% set followed_urls = [] %}
+  {% include "social/_actor_list_items.html" %}
+</div>
+{% endblock %}