This patch adds a reverse proxy in front of novnc and playwright
server inside the container.
As a result:
- container exposes a single HTTP port to the host
- all Playwright clients can connect using this exposed port, e.g.
`http://127.0.0.1:5400`
- navigating to the exposed port in the browser lands on a nice HTML
page
with a link to view container screen
- users can also manually navigate to `http://127.0.0.1:5400/screen` to
view screen
