Click stability: only a hand controller's press starts it

The 3D mouse drives SteamVR's laser through the ft_pointer virtual
controller, so its events reach the screens the same way a controller's
do. The filter held every press, which turned the mouse's short drags
(selecting a character or two, nudging a slider) into clicks. Mark
button events from hand controllers and start the filter only on those.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

screens/vr.cpp

@@ -1741,6 +1741,7 @@ void ft_vr_poll(void (*handle)(const struct ft_event *, void *), void *data) {
                     e.type = FT_BUTTON;
                     e.button = LinuxButton(ev.data.mouse.button);
                     e.pressed = ev.eventType == vr::VREvent_MouseButtonDown;
+                    e.controller = IsHandController(ev.trackedDeviceIndex);
                     at();
                     if (!e.pressed && s.titleCarry) e.x = s.carryX, e.y = s.carryY, s.titleCarry = false;
                     if (e.pressed) {