updates and bug fixes

lib/layout/breakpoints.dart

@@ -0,0 +1,13 @@
+import 'package:flutter/widgets.dart';
+
+/// Width at/above which the UI switches to a wide, side-by-side layout —
+/// Material's "expanded" window class, i.e. tablet landscape (iPad). Keyed off
+/// width rather than raw orientation so a phone in landscape (wide but short)
+/// stays on the compact layout.
+const double kWideBreakpoint = 840;
+
+/// Whether the current window is wide enough for the side-by-side layout.
+/// Uses [MediaQuery.sizeOf] so callers rebuild only when the size actually
+/// changes, not on every unrelated MediaQuery update.
+bool isWideLayout(BuildContext context) =>
+    MediaQuery.sizeOf(context).width >= kWideBreakpoint;