[deploy] Emit frontend bundle as ESM for browser

public/ts-build/ui/modal.js

@@ -1,7 +1,3 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.showModal = showModal;
-exports.hideModal = hideModal;
 let activeModal = null;
 let backdrop = null;
 function ensureBackdrop() {
@@ -13,14 +9,14 @@ function ensureBackdrop() {
     document.body.appendChild(backdrop);
     return backdrop;
 }
-function showModal(content) {
+export function showModal(content) {
     const bd = ensureBackdrop();
     if (!content.parentElement)
         bd.appendChild(content);
     activeModal = content;
     bd.classList.add('show');
 }
-function hideModal() {
+export function hideModal() {
     if (backdrop)
         backdrop.classList.remove('show');
     activeModal = null;