feat: add fediverse follow me sidebar widget

Reuses the existing fediverseInteract Alpine.js component to let
visitors follow the site author from their own fediverse instance.
Registered in all three sidebar routers (homepage, blog listing,
blog post) as widget type "fediverse-follow".

_includes/components/blog-sidebar.njk

@@ -42,6 +42,8 @@
         <script>initPagefind("#blog-sidebar-search");</script>
       </div>
       </is-land>
+    {% elif widget.type == "fediverse-follow" %}
+      {% include "components/widgets/fediverse-follow.njk" %}
     {% elif widget.type == "custom-html" %}
       {% set wConfig = widget.config or {} %}
       <is-land on:visible>

_includes/components/homepage-sidebar.njk

@@ -29,6 +29,8 @@
       {% include "components/widgets/webmentions.njk" %}
     {% elif widget.type == "recent-comments" %}
       {% include "components/widgets/recent-comments.njk" %}
+    {% elif widget.type == "fediverse-follow" %}
+      {% include "components/widgets/fediverse-follow.njk" %}
     {% elif widget.type == "custom-html" %}
       {# Custom content widget #}
       {% set wConfig = widget.config or {} %}

_includes/components/sidebar.njk

@@ -38,6 +38,8 @@
       </is-land>
     {% elif widget.type == "webmentions" %}
       {% include "components/widgets/webmentions.njk" %}
+    {% elif widget.type == "fediverse-follow" %}
+      {% include "components/widgets/fediverse-follow.njk" %}
     {% elif widget.type == "custom-html" %}
       {% set wConfig = widget.config or {} %}
       <is-land on:visible>

_includes/components/widgets/fediverse-follow.njk

@@ -0,0 +1,76 @@
+{# Fediverse Follow Me Widget — uses the fediverseInteract Alpine.js component #}
+{# Requires fediverse-interact.js loaded in base.njk (already present) #}
+{# Determines actor URI from site social links: prefers self-hosted AP, falls back to Mastodon #}
+
+{% set actorUrl = "" %}
+{% for link in site.social %}
+  {% if link.icon == "activitypub" and not actorUrl %}
+    {% set actorUrl = link.url %}
+  {% endif %}
+{% endfor %}
+{% if not actorUrl %}
+  {% for link in site.social %}
+    {% if link.icon == "mastodon" and not actorUrl %}
+      {% set actorUrl = link.url %}
+    {% endif %}
+  {% endfor %}
+{% endif %}
+
+{% if actorUrl %}
+<is-land on:visible>
+<div class="widget" x-data="fediverseInteract('{{ actorUrl }}')">
+  <h3 class="widget-title">Follow Me</h3>
+  <p class="text-sm text-surface-500 dark:text-surface-400 mb-3">Follow me from your fediverse instance.</p>
+  <a href="{{ actorUrl }}"
+     @click="handleClick($event)"
+     class="inline-flex items-center gap-2 px-4 py-2 rounded-lg bg-[#a730b8]/10 text-[#a730b8] hover:bg-[#a730b8]/20 transition-colors text-sm font-medium cursor-pointer"
+     title="Follow from your fediverse instance (Shift+click to change)">
+    <svg class="w-4 h-4" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+      <path d="M16 21v-2a4 4 0 0 0-4-4H5a4 4 0 0 0-4 4v2"/><circle cx="8.5" cy="7" r="4"/><line x1="20" y1="8" x2="20" y2="14"/><line x1="23" y1="11" x2="17" y2="11"/>
+    </svg>
+    <span>Follow on the Fediverse</span>
+  </a>
+
+  {# Modal overlay for instance entry — same pattern as post.njk #}
+  <template x-if="showModal">
+    <div class="fixed inset-0 z-50 flex items-center justify-center p-4" @keydown.escape.window="showModal = false">
+      <div class="fixed inset-0 bg-black/40"
+           x-transition:enter="transition ease-out duration-200"
+           x-transition:enter-start="opacity-0"
+           x-transition:enter-end="opacity-100"
+           x-transition:leave="transition ease-in duration-150"
+           x-transition:leave-start="opacity-100"
+           x-transition:leave-end="opacity-0"
+           @click="showModal = false"></div>
+      <div class="relative bg-white dark:bg-surface-800 rounded-xl shadow-xl w-full max-w-sm p-6"
+           x-transition:enter="transition ease-out duration-200"
+           x-transition:enter-start="opacity-0 scale-95"
+           x-transition:enter-end="opacity-100 scale-100"
+           x-transition:leave="transition ease-in duration-150"
+           x-transition:leave-start="opacity-100 scale-100"
+           x-transition:leave-end="opacity-0 scale-95"
+           @click.stop>
+        <h3 class="text-lg font-semibold text-surface-900 dark:text-surface-100 mb-1">Follow on the Fediverse</h3>
+        <p class="text-sm text-surface-500 dark:text-surface-400 mb-4">Enter your instance to follow this account.</p>
+        <input x-ref="instanceInput"
+               x-model="instance"
+               @keydown.enter.prevent="confirm()"
+               type="text"
+               placeholder="mastodon.social"
+               class="w-full px-3 py-2 border border-surface-300 dark:border-surface-600 rounded-lg bg-white dark:bg-surface-700 text-surface-900 dark:text-surface-100 placeholder-surface-400 focus:outline-none focus:ring-2 focus:ring-[#a730b8] focus:border-transparent text-sm">
+        <div class="flex gap-3 mt-4">
+          <button @click="showModal = false"
+                  class="flex-1 px-4 py-2 text-sm font-medium text-surface-600 dark:text-surface-300 bg-surface-100 dark:bg-surface-700 hover:bg-surface-200 dark:hover:bg-surface-600 rounded-lg transition-colors">
+            Cancel
+          </button>
+          <button @click="confirm()"
+                  class="flex-1 px-4 py-2 text-sm font-medium text-white bg-[#a730b8] hover:bg-[#a730b8]/80 rounded-lg transition-colors">
+            Go
+          </button>
+        </div>
+      </div>
+    </div>
+  </template>
+</div>
+</is-land>
+{% endif %}