add login/sign-up page with dark/light mode

node_modules/next/dist/server/app-render/flight-render-result.d.ts

@@ -0,0 +1,7 @@
+import RenderResult, { type RenderResultMetadata } from '../render-result';
+/**
+ * Flight Response is always set to RSC_CONTENT_TYPE_HEADER to ensure it does not get interpreted as HTML.
+ */
+export declare class FlightRenderResult extends RenderResult {
+    constructor(response: string | ReadableStream<Uint8Array>, metadata?: RenderResultMetadata, waitUntil?: Promise<unknown>);
+}