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

packages/api/src/board-server.ts

@@ -0,0 +1,16 @@
+import { cache } from "react";
+
+import { createRscTrpcContext } from "./rsc-context";
+import { boardRouter } from "./router/board";
+
+const createBoardCallerAsync = async () => boardRouter.createCaller(await createRscTrpcContext());
+
+export const getBoardByNameAsync = cache(async (name: string) => {
+  const caller = await createBoardCallerAsync();
+  return await caller.getBoardByName({ name });
+});
+
+export const getHomeBoardAsync = cache(async () => {
+  const caller = await createBoardCallerAsync();
+  return await caller.getHomeBoard();
+});