Initial commit: notification-elements-demo app

Interactive Angular 19 demo for @sda/notification-elements-ui with
6 sections: Bell & Feed, Notification Center, Inbox, Comments &
Threads, Mention Input, and Full-Featured layout. Includes mock
data, dark mode toggle, and real-time event log.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

node_modules/webpack-dev-middleware/dist/utils/escapeHtml.js

@@ -0,0 +1,55 @@
+"use strict";
+
+const matchHtmlRegExp = /["'&<>]/;
+
+/**
+ * @param {string} string raw HTML
+ * @returns {string} escaped HTML
+ */
+function escapeHtml(string) {
+  const str = `${string}`;
+  const match = matchHtmlRegExp.exec(str);
+  if (!match) {
+    return str;
+  }
+  let escape;
+  let html = "";
+  let index = 0;
+  let lastIndex = 0;
+  for (({
+    index
+  } = match); index < str.length; index++) {
+    switch (str.charCodeAt(index)) {
+      // "
+      case 34:
+        escape = "&quot;";
+        break;
+      // &
+      case 38:
+        escape = "&amp;";
+        break;
+      // '
+      case 39:
+        escape = "&#39;";
+        break;
+      // <
+      case 60:
+        escape = "&lt;";
+        break;
+      // >
+      case 62:
+        escape = "&gt;";
+        break;
+      default:
+        // eslint-disable-next-line no-continue
+        continue;
+    }
+    if (lastIndex !== index) {
+      html += str.substring(lastIndex, index);
+    }
+    lastIndex = index + 1;
+    html += escape;
+  }
+  return lastIndex !== index ? html + str.substring(lastIndex, index) : html;
+}
+module.exports = escapeHtml;