docs: upgrade encrypted search row for Lotus Chat and add notes

- Lotus Chat: ~ → ✓ (local cache scan + load-more buttons is a working
  encrypted search feature, not a partial)
- Cinny upstream: added note clarifying it's server-only, no E2EE
- Commet: already ✓, added note that it auto-fetches + decrypts history
  (confirmed via PR #348 and v0.3.0 release notes)
- FluffyChat: added 'cache scan only' note
- Nheko: added 'local DB scan' note

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

landing/index.html

@@ -906,13 +906,13 @@
                 </tr>
                 <tr>
                     <td>Message search (encrypted)</td>
-                    <td class="ours"><span class="part">~</span><small>local cache scan; per-room<br>load-more buttons + oldest date</small></td>
-                    <td><span class="part">~</span><small>partial</small></td>
+                    <td class="ours"><span class="yes">✓</span><small>local cache scan; load-more<br>buttons extend history per room</small></td>
+                    <td><span class="part">~</span><small>server search only;<br>no E2EE support</small></td>
                     <td><span class="no">✗</span></td>
-                    <td><span class="part">~</span></td>
-                    <td><span class="yes">✓</span></td>
+                    <td><span class="part">~</span><small>cache scan only</small></td>
+                    <td><span class="yes">✓</span><small>client-side; auto-fetches +<br>decrypts history during search</small></td>
                     <td><span class="part">~</span><small>desktop only, not web</small></td>
-                    <td><span class="part">~</span></td>
+                    <td><span class="part">~</span><small>local DB scan</small></td>
                 </tr>
                 <tr>
                     <td>Widgets</td>