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/semver/internal/identifiers.js

@@ -0,0 +1,23 @@
+const numeric = /^[0-9]+$/
+const compareIdentifiers = (a, b) => {
+  const anum = numeric.test(a)
+  const bnum = numeric.test(b)
+
+  if (anum && bnum) {
+    a = +a
+    b = +b
+  }
+
+  return a === b ? 0
+    : (anum && !bnum) ? -1
+    : (bnum && !anum) ? 1
+    : a < b ? -1
+    : 1
+}
+
+const rcompareIdentifiers = (a, b) => compareIdentifiers(b, a)
+
+module.exports = {
+  compareIdentifiers,
+  rcompareIdentifiers,
+}