Fix operators tabbing out of the Windows kiosk

On Windows the station kiosk launched Microsoft Edge with generic full-screen flags, which hide the toolbars but leave an ordinary browser session behind them, so pressing Ctrl+T opened a tab on the MSN start page.

• Fixed the kiosk launch on Windows to use Edge's own kiosk mode, which serves a single site in a private session and blocks new tabs and new windows.
• Pinned the kiosk idle timeout to zero, so the window can never be closed and reset under a running test.
• Rewrote the message shown when the local UI cannot bind its port, which blamed privileged ports on every platform and sent Windows operators looking for administrator rights instead of the reserved port ranges that were the real cause.