fix: set control modifier before xinput scroll dispatch

Branch on UseInputDriver to avoid dummy driver log spam while ensuring
the Ctrl modifier is set before xf86-input-neko posts the motion event.
The XTest fallback still handles controlKey atomically under a single lock.

Made-with: Cursor

Author: hiroTamada

server/internal/desktop/xorg.go

@@ -19,17 +19,21 @@ func (manager *DesktopManagerCtx) GetCursorPosition() (int, int) {
 }
 
 func (manager *DesktopManagerCtx) Scroll(deltaX, deltaY int, controlKey bool) {
-	// Try xinput driver first (XI2.1 smooth scrolling via xf86-input-neko)
-	if err := manager.input.Scroll(int32(deltaX), int32(deltaY)); err == nil {
+	if manager.config.UseInputDriver {
+		// XI2.1 smooth scrolling via xf86-input-neko: set modifier before the
+		// driver posts the motion event so the X server sees Ctrl held.
 		if controlKey {
 			xorg.SetKeyboardModifier(xorg.KbdModControl, true)
 			defer xorg.SetKeyboardModifier(xorg.KbdModControl, false)
 		}
-		return
+		if err := manager.input.Scroll(int32(deltaX), int32(deltaY)); err != nil {
+			manager.logger.Warn().Err(err).Msg("xinput scroll failed, falling back to XTest")
+			xorg.Scroll(deltaX, deltaY, false)
+		}
+	} else {
+		// XTest fallback — handles controlKey atomically under a single X11 lock
+		xorg.Scroll(deltaX, deltaY, controlKey)
 	}
-
-	// XTest fallback — handles controlKey atomically under a single X11 lock
-	xorg.Scroll(deltaX, deltaY, controlKey)
 }
 
 func (manager *DesktopManagerCtx) ButtonDown(code uint32) error {