[Feature]: --angle for ui touch --gesture pinch / stretch #1093

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

Part of #1084 (item 5).

touch --gesture pinch and stretch always move the two fingers along the x-axis. A diagonal pinch is the only way to exercise a zoom that tracks both axes, so callers currently inject their own InjectTouchInput sequence.

Describe the solution you'd like

winapp ui touch <selector> -a <app> --gesture pinch --distance 300 --angle 45

--angle is the finger axis in degrees (0 = horizontal, the current behavior and the default; 90 = vertical). It is valid only with pinch or stretch.

Additional context

The finger paths are computed in PointerGesturePlanner (WinApp.UIAutomation/Input/PointerGesturePlanner.cs); the fix rotates the two offset vectors around the anchor point.