[Feature]: Horizontal mouse wheel for ui scroll #1092

Is your feature request related to a problem? Please describe.

Part of #1084 (item 4).

winapp ui scroll --wheel N sends vertical wheel notches only. Controls that pan on a horizontal wheel (tilt wheel or touchpad), such as a calendar timeline, can't be driven without injecting MOUSEEVENTF_HWHEEL by hand.

Describe the solution you'd like

winapp ui scroll <selector> -a <app> --wheel-horizontal 3    # 3 notches right; negative = left

(or --wheel N --axis horizontal; pick one shape and use it consistently). Under the hood this is the same as --wheel, but the input uses MOUSEEVENTF_HWHEEL.

Additional context

The wheel input is built in MouseInput.CreateWheelInput (WinApp.UIAutomation/Input/MouseInput.cs).