release: v4.8.9 security hardening patch

- upgrade DOMPurify to patched release (fixes high-severity XSS GHSA-87xg-pxx2-7hvx)
- upgrade esbuild build dependency; npm audit now reports 0 vulnerabilities
- stop tracking config/ice-servers.js (TURN credentials); add example template
- production logger no longer prints error context or info/debug output
- bump version to 4.8.9 across header, manifest, README, init message
- update SECURITY.md supported-release table to v4.8.x

dist/qr-local.js

@@ -5,7 +5,11 @@ var __getOwnPropNames = Object.getOwnPropertyNames;
 var __getProtoOf = Object.getPrototypeOf;
 var __hasOwnProp = Object.prototype.hasOwnProperty;
 var __commonJS = (cb, mod) => function __require() {
-  return mod || (0, cb[__getOwnPropNames(cb)[0]])((mod = { exports: {} }).exports, mod), mod.exports;
+  try {
+    return mod || (0, cb[__getOwnPropNames(cb)[0]])((mod = { exports: {} }).exports, mod), mod.exports;
+  } catch (e) {
+    throw mod = 0, e;
+  }
 };
 var __copyProps = (to, from, except, desc) => {
   if (from && typeof from === "object" || typeof from === "function") {