flua UI viewer — served by flua --ui at this address, it polls
GET /flua/devices (the QAs you run in flua, not the whole HC3),
renders properties.uiView (live state merged from
device.view, the target of QuickApp:updateView),
prepends the device type's default view (On/Off buttons, state label,
dimmer — from GET /flua/embeddedUI), and injects interactions
via GET /plugins/callUIEvent or device actions — the same
contract the real HC3 UI uses. The API field can point at another
machine running flua (leave user/pass empty; they exist for a real HC3).