Install app

Requests an app install on the device. The request body must supply exactly one of an Android packageName or an iOS bundleId; protected packages are rejected. background (default false) selects the response contract: false installs inline and returns the outcome directly (200 on success, an error status on failure); true accepts the request and runs the download + install in the background, returning 202 immediately — poll list-app-installs for the backend's view of that attempt's status. Refuses with 409 once 2 other installs are already running on the device, in either mode; a repeat request for an app that already has an install running is also refused with 409 rather than superseding it — retry once that attempt reaches a terminal state.