feat(boards): add responsive layout system (#2271)

packages/old-import/src/mappers/map-breakpoint.ts

@@ -0,0 +1,18 @@
+import type { BoardSize } from "@homarr/old-schema";
+
+/**
+ * Copied from https://github.com/ajnart/homarr/blob/274eaa92084a8be4d04a69a87f9920860a229128/src/components/Dashboard/Wrappers/gridstack/store.tsx#L21-L30
+ * @param screenSize board size
+ * @returns layout breakpoint for the board
+ */
+export const mapBreakpoint = (screenSize: BoardSize) => {
+  switch (screenSize) {
+    case "lg":
+      return 1400;
+    case "md":
+      return 800;
+    case "sm":
+    default:
+      return 0;
+  }
+};