feat: the panel's own confirm and prompt dialogs everywhere; the assistant's field is one line with a square send button

internal/server/web/templates/app.html

@@ -195,6 +195,7 @@
 <div class="toast" id="toast"></div>
 <script>window.APP = {admin: {{.IsAdmin}}, open: {{.Open}}, dialog: {{.Dialog}}, editLimit: {{.EditLimit}}};</script>
 <script src="{{asset "wsutil.js"}}"></script>
+<script src="{{asset "ui.js"}}"></script>
 <script src="{{asset "xterm.js"}}"></script>
 <script src="{{asset "addon-fit.js"}}"></script>
 <script src="{{asset "app.js"}}"></script>