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/@npmcli/git/lib/find.js

@@ -0,0 +1,15 @@
+const is = require('./is.js')
+const { dirname } = require('path')
+
+module.exports = async ({ cwd = process.cwd(), root } = {}) => {
+  while (true) {
+    if (await is({ cwd })) {
+      return cwd
+    }
+    const next = dirname(cwd)
+    if (cwd === root || cwd === next) {
+      return null
+    }
+    cwd = next
+  }
+}