Add mouse window controls and finer display scaling (#63)

Add configurable mouse and wheel bindings, window move and resize, tab drops, cross-output dragging, and device settings. Adjust display scaling in 0.05 increments.

Preserve opposite-edge positioning during scrolling resizes and show rows for edge drops into tabbed columns.

scripts/tests/fixtures/presentation.c

@@ -74,6 +74,7 @@ static const struct wl_registry_listener registry_listener = {global, removed};
 static void configure(void *data, struct xdg_surface *xdg, uint32_t serial) {
     (void)data;
     xdg_surface_ack_configure(xdg, serial);
+    if (!mapped) return;
     xdg_surface_set_window_geometry(xdg, 0, 0, width, height);
     wl_surface_attach(surface, buffer, 0, 0);
     wl_surface_damage(surface, 0, 0, width, height);