Replace the very-narrow 24px edge-swipe trigger with a left band of ~20% of the
viewport width (EDGE_FRACTION) so the back-swipe is easy to reach, keeping the
simple instant-navigate behaviour (the route slide plays the animation). A
hit-test keeps the wider band clear of the rack, a draggable pending tile, a
zoomed-in board and text inputs, so it never hijacks those drags.
Test: e2e (Chromium+WebKit) — the band swipe returns to the lobby; a swipe
starting on the rack does not navigate.
Ilia Denisov