feat: ActivityPub reader — timeline, notifications, compose, moderation

Add a dedicated fediverse reader view with:
- Timeline view showing posts from followed accounts with threading,
  content warnings, boosts, and media display
- Compose form with dual-path posting (quick AP reply + Micropub blog post)
- Native AP interactions (like, boost, reply, follow/unfollow)
- Notifications view for likes, boosts, follows, mentions, replies
- Moderation tools (mute/block actors, keyword filters)
- Remote actor profile pages with follow state
- Automatic timeline cleanup with configurable retention
- CSRF protection, XSS prevention, input validation throughout

Removes Microsub bridge dependency — AP content now lives in its own
MongoDB collections (ap_timeline, ap_notifications, ap_interactions,
ap_muted, ap_blocked).

Bumps version to 1.1.0.

views/partials/ap-notification-card.njk

@@ -0,0 +1,58 @@
+{# Notification card partial #}
+
+<div class="ap-notification{% if not item.read %} ap-notification--unread{% endif %}">
+  {# Type icon #}
+  <div class="ap-notification__icon">
+    {% if item.type == "like" %}
+      ❤
+    {% elif item.type == "boost" %}
+      🔁
+    {% elif item.type == "follow" %}
+      👤
+    {% elif item.type == "reply" %}
+      💬
+    {% elif item.type == "mention" %}
+      @
+    {% endif %}
+  </div>
+
+  {# Notification body #}
+  <div class="ap-notification__body">
+    <span class="ap-notification__actor">
+      <a href="{{ item.actorUrl }}">{{ item.actorName }}</a>
+    </span>
+
+    <span class="ap-notification__action">
+      {% if item.type == "like" %}
+        {{ __("activitypub.notifications.liked") }}
+      {% elif item.type == "boost" %}
+        {{ __("activitypub.notifications.boostedPost") }}
+      {% elif item.type == "follow" %}
+        {{ __("activitypub.notifications.followedYou") }}
+      {% elif item.type == "reply" %}
+        {{ __("activitypub.notifications.repliedTo") }}
+      {% elif item.type == "mention" %}
+        {{ __("activitypub.notifications.mentionedYou") }}
+      {% endif %}
+    </span>
+
+    {% if item.targetUrl %}
+      <a href="{{ item.targetUrl }}" class="ap-notification__target">
+        {{ item.targetName or item.targetUrl }}
+      </a>
+    {% endif %}
+
+    {% if item.content and item.content.text %}
+      <div class="ap-notification__excerpt">
+        {{ item.content.text | truncate(200) }}
+      </div>
+    {% endif %}
+  </div>
+
+  {# Timestamp #}
+  {% if item.published %}
+    <time datetime="{{ item.published }}" class="ap-notification__time">
+      {{ item.published | date("PPp") }}
+    </time>
+  {% endif %}
+</div>