Ze web configuration demo

1. Open the local Ze HTTPS interface.
2. Sign in as the local administrator.
3. Open System / Identity in configuration mode.
4. Change the hostname from ze-demo to edge-demo.
5. Save the draft and open Review & Commit.
6. Verify the diff contains `host edge-demo`.
7. Confirm the commit.
8. Reload the setting and verify the active hostname is edge-demo.

Expected result: Ze commits the browser user's isolated draft and the active YANG-backed hostname reads `edge-demo`.