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/pacote/lib/util/cache-dir.js

@@ -0,0 +1,15 @@
+const { resolve } = require('node:path')
+const { tmpdir, homedir } = require('node:os')
+
+module.exports = (fakePlatform = false) => {
+  const temp = tmpdir()
+  const uidOrPid = process.getuid ? process.getuid() : process.pid
+  const home = homedir() || resolve(temp, 'npm-' + uidOrPid)
+  const platform = fakePlatform || process.platform
+  const cacheExtra = platform === 'win32' ? 'npm-cache' : '.npm'
+  const cacheRoot = (platform === 'win32' && process.env.LOCALAPPDATA) || home
+  return {
+    cacache: resolve(cacheRoot, cacheExtra, '_cacache'),
+    tufcache: resolve(cacheRoot, cacheExtra, '_tuf'),
+  }
+}