feat: Initial release v0.1.0

WP FediStream - Stream music over ActivityPub

Features:
- Custom post types: Artist, Album, Track, Playlist
- Custom taxonomies: Genre, Mood, License
- User roles: Artist, Label
- Admin dashboard with statistics
- Frontend templates and shortcodes
- Audio player with queue management
- ActivityPub integration with actor support
- WooCommerce product types for albums/tracks
- User library with favorites and history
- Notification system (in-app and email)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

templates/shortcodes/artists-grid.twig

@@ -0,0 +1,18 @@
+{# Artists grid shortcode template #}
+<div class="fedistream-shortcode fedistream-shortcode--artists">
+    {% if title %}
+        <h3 class="fedistream-shortcode__title">{{ title }}</h3>
+    {% endif %}
+
+    {% if posts is not empty %}
+        <div class="fedistream-grid fedistream-grid--artists fedistream-grid--cols-{{ columns }}">
+            {% for post in posts %}
+                {% include 'partials/card-artist.twig' with { post: post } %}
+            {% endfor %}
+        </div>
+    {% else %}
+        <div class="fedistream-empty">
+            <p>{{ __('No artists found.', 'wp-fedistream') }}</p>
+        </div>
+    {% endif %}
+</div>