fix(koreader): keep each device's layout at every interface size

Layout breakpoints use the screen width at 1x, so Interface size scales text,
icons and spacing without dropping Home columns or detail panes. Every page,
sheet and widget picks a layout that fits instead of cutting text or leaving
gaps; search becomes balanced list-row sections, Edit Home keeps hidden widgets,
stock KOReader messages become BookOrbit toasts, and the plugin is 2.1.0.

koreader-plugin/bookorbit.koplugin/bookorbit_toast.lua

@@ -37,7 +37,7 @@ local function bottomGap()
 end
 
 local function maxWidth()
-    local W = BoardMetrics.get().W
+    local W = BoardMetrics.layoutW()
     local mx = px(W >= 900 and 28 or W >= 700 and 24 or W >= 560 and 20 or 16)
     return Screen:getWidth() - 2 * mx
 end