feat: red text and border on every close button

internal/server/web/templates/terminal.html

@@ -54,7 +54,7 @@
   <button type="button" data-a="copy">Копировать</button>
   <button type="button" class="btn ghost" data-a="paste">Вставить</button>
   <button type="button" class="btn ghost" data-a="all">Всё</button>
-  <button type="button" class="btn ghost" data-a="close" aria-label="Закрыть">×</button>
+  <button type="button" class="btn ghost close" data-a="close" aria-label="Закрыть">×</button>
 </div>
 <div class="keys" id="keys">
   <button type="button" data-k="esc">ESC</button>