PadRIO: pod stick convention is opposite XInput on both axes

Playtest feedback: X and Y from the Xbox controller were both inverted.
Negate both by default (pad and WASD go through the same assignment, so
they stay consistent); L4PADFLIP now flips back toward raw XInput
orientation per axis.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

MUNGA_L4/L4PADRIO.cpp

@@ -347,8 +347,11 @@ void
 	Throttle   = throttleAccum;
 	LeftPedal  = Clamp01(left_pedal);
 	RightPedal = Clamp01(right_pedal);
-	JoystickX  = invertX ? -x : x;
-	JoystickY  = invertY ? -y : y;
+	// The pod's stick convention is opposite the XInput axes on both X and
+	// Y (confirmed in playtest), so the default is negated; L4PADFLIP
+	// flips back per axis.
+	JoystickX  = invertX ? x : -x;
+	JoystickY  = invertY ? y : -y;
 
 	//---------------------------------------------------------------
 	// Emit an analog event when asked to, or when anything moved