feat(react/widgets): port close zen button

apps/client/src/widgets/close_zen_button.tsx

@@ -0,0 +1,25 @@
+import { useState } from "preact/hooks";
+import { t } from "../services/i18n";
+import ActionButton from "./react/ActionButton";
+import { useTriliumEvent } from "./react/hooks";
+import "./close_zen_button.css";
+
+export default function CloseZenModeButton() {
+    const [ zenModeEnabled, setZenModeEnabled ] = useState(false);
+
+    useTriliumEvent("zenModeChanged", ({ isEnabled }) => {
+        setZenModeEnabled(isEnabled);
+    });
+
+    return (
+        <div class={`close-zen-container ${!zenModeEnabled ? "hidden-ext" : ""}`}>
+            {zenModeEnabled && (
+                <ActionButton
+                    icon="bx bxs-yin-yang"
+                    triggerCommand="toggleZenMode"
+                    text={t("zen_mode.button_exit")}
+                />
+            )}
+        </div>
+    )
+}