perf: cut cold route compilation and unblock preview images (#6441)

packages/api/src/user-server.ts

@@ -0,0 +1,24 @@
+import { cache } from "react";
+
+import { db, eq } from "@homarr/db";
+import { users } from "@homarr/db/schema";
+
+// Keep the authenticated user lookup shared across nested RSC layouts. React
+// clears this memo between requests, so authorization changes cannot leak.
+export const getRscUserSettingsAsync = cache(async (userId: string) =>
+  db.query.users.findFirst({
+    columns: {
+      homeBoardId: true,
+      mobileHomeBoardId: true,
+      firstDayOfWeek: true,
+      pingIconsEnabled: true,
+      enableRightClickOnWidgets: true,
+      defaultSearchEngineId: true,
+      openSearchInNewTab: true,
+      ddgBangs: true,
+      completedManageTour: true,
+      completedBoardTour: true,
+    },
+    where: eq(users.id, userId),
+  }),
+);