fix(board): align edit mode with dev's removal of loading overlay

Remove useIsBoardReady and LoadingOverlay from edit mode board,
aligning with the dev branch's perf improvement that shows the board
immediately without waiting for ready state.

apps/nextjs/src/app/[locale]/boards/(content)/_edit-board.tsx

@@ -1,41 +1,30 @@
 "use client";
 
-import { Box, LoadingOverlay, Stack } from "@mantine/core";
+import { Stack } from "@mantine/core";
 
 import { useCurrentLayout, useRequiredBoard } from "@homarr/boards/context";
 
 import { BoardCategorySection } from "~/components/board/sections/category-section";
 import { BoardEmptySection } from "~/components/board/sections/empty-section";
-import { fullHeightWithoutHeaderAndFooter } from "~/constants";
-import { useIsBoardReady } from "./_ready-context";
 
 const EditModeBoard = () => {
   const board = useRequiredBoard();
   const currentLayoutId = useCurrentLayout();
-  const isReady = useIsBoardReady();
 
   const fullWidthSortedSections = board.sections
     .filter((section) => section.kind === "empty" || section.kind === "category")
     .sort((sectionA, sectionB) => sectionA.yOffset - sectionB.yOffset);
 
   return (
-    <Box h="100%" pos="relative">
-      <LoadingOverlay
-        visible={!isReady}
-        transitionProps={{ duration: 500 }}
-        loaderProps={{ size: "lg" }}
-        h={fullHeightWithoutHeaderAndFooter}
-      />
-      <Stack h="100%" style={{ visibility: isReady ? "visible" : "hidden" }}>
-        {fullWidthSortedSections.map((section) =>
-          section.kind === "empty" ? (
-            <BoardEmptySection key={`${currentLayoutId}-${section.id}`} section={section} />
-          ) : (
-            <BoardCategorySection key={`${currentLayoutId}-${section.id}`} section={section} />
-          ),
-        )}
-      </Stack>
-    </Box>
+    <Stack h="100%">
+      {fullWidthSortedSections.map((section) =>
+        section.kind === "empty" ? (
+          <BoardEmptySection key={`${currentLayoutId}-${section.id}`} section={section} />
+        ) : (
+          <BoardCategorySection key={`${currentLayoutId}-${section.id}`} section={section} />
+        ),
+      )}
+    </Stack>
   );
 };