feat: watch issues from mobile search (Closes #1290)

frontend/index.html

@@ -957,7 +957,7 @@
         <button id="queue-search-result" type="button" hidden>Assign &amp; add to Today</button>
         <button id="plan-search-result" type="button" hidden>Plan ahead</button>
         <button id="start-search-result" type="button" hidden>Assign &amp; start</button>
-
+        <button id="watch-search-result" type="button" hidden>Watch issue</button>
       </div>
       <button id="share-search-result" type="button" disabled>Share result</button>
       <a id="open-search-result-gitea" href="#" target="_blank" rel="noopener noreferrer">Open in Gitea</a>