iosDeviceChecks now verifies devicectl, iproxy on PATH, a connected+paired
device (via ios.ConnectedDevices), and App Store Connect signing creds (via
ioscompanion.VerifyDeviceSigning). The retired JVM sidecar checks stay only
under android.
ResolveDevice parses xcrun devicectl list devices into Device{Name,
HardwareUDID, CoreDeviceID}: the hardware UDID feeds xcodebuild/iproxy
and the CoreDevice id feeds devicectl install. Matches by name or either
id; errors list candidates on none/ambiguous. Fixes the stale sidecar
comment on ResolveTarget.