clean up unused code and create login callback api endpoints

Signed-off-by: Chloe <pinkcloudvnn@gmail.com>

app/api/authorize/route.ts

@@ -0,0 +1,9 @@
+import { authorize, getOrigin } from 'lib/shopify/auth';
+import { NextRequest, NextResponse } from 'next/server';
+
+export const runtime = 'edge';
+
+export async function GET(request: NextRequest): Promise<NextResponse> {
+  const origin = getOrigin(request);
+  return await authorize(request, origin);
+}