feat: add per-message read receipts row and update Lotus Chat feature list

Add per-message read receipts comparison row (8-col, including new official
Cinny column from dc8f588). Update Lotus Chat feature description to include
per-message read receipt avatars and chat wallpaper in calls.

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

landing/index.html

@@ -554,7 +554,7 @@
                 </a>
             </div>
             <p class="also-available">
-                Our Lotus Guild fork of Cinny adds: incoming call ring + Answer/Decline (DMs &amp; group chats), GIF picker (Giphy), draggable+resizable picture-in-picture call window, poll display &amp; voting, message forwarding, image/video captions, location sharing (map view + send), deleted message placeholders, and the Lotus Terminal design theme.
+                Our Lotus Guild fork of Cinny adds: incoming call ring + Answer/Decline (DMs &amp; group chats), GIF picker (Giphy), draggable+resizable picture-in-picture call window, poll display &amp; voting, message forwarding, image/video captions, location sharing (map view + send), deleted message placeholders, per-message read receipt avatars (click for full list with timestamps), chat wallpaper in calls, and the Lotus Terminal design theme.
                 Prefer the unmodified upstream? <a href="https://cinny.in" target="_blank" rel="noopener">cinny.in</a> works with our homeserver &mdash; set it to <code style="font-size:0.8em;color:#e88;">matrix.lotusguild.org</code>.
             </p>
 
@@ -987,6 +987,16 @@
                     <td><span class="yes">✓</span></td>
                     <td><span class="no">✗</span></td>
                 </tr>
+                <tr>
+                    <td>Per-message read receipts<small>who read each message</small></td>
+                    <td class="ours"><span class="yes">✓</span><small>avatar pill below message,<br>click for list + timestamps</small></td>
+                    <td><span class="no">✗</span></td>
+                    <td><span class="yes">✓</span><small>avatar thumbnails</small></td>
+                    <td><span class="yes">✓</span></td>
+                    <td><span class="yes">✓</span></td>
+                    <td><span class="yes">✓</span><small>avatar row below message</small></td>
+                    <td><span class="yes">✓</span></td>
+                </tr>
                 <tr>
                     <td>Push notifications</td>
                     <td class="ours"><span class="part">~</span><small>web push only</small></td>