feat: reply and continue from mobile search (Closes #805)

frontend/index.html

@@ -472,6 +472,15 @@
       <button id="retry-search-preview-conversation" type="button" hidden>Retry conversation</button>
       <button id="load-older-search-preview-comments" type="button" hidden>Load older messages</button>
     </section>
+    <section class="search-preview-reply" aria-labelledby="search-preview-reply-title" hidden>
+      <h2 id="search-preview-reply-title">Reply</h2>
+      <textarea id="search-preview-reply" maxlength="10000" placeholder="Write a reply"></textarea>
+      <div id="search-preview-reply-status" class="small" aria-live="polite"></div>
+      <div class="search-preview-reply-actions">
+        <button id="send-search-preview-reply" type="button">Send</button>
+        <button id="send-search-preview-reply-next" type="button">Send &amp; next</button>
+      </div>
+    </section>
     <div class="search-preview-actions">
       <nav class="search-preview-navigation" aria-label="Search result navigation" hidden>
         <button id="previous-search-result" type="button">Previous</button>