Revert "chore: drop support for legacy shared url (#5347)"

This reverts commit ee37447.

Author: TrySound

apps/builder/app/routes/builder.$projectId.tsx

@@ -0,0 +1,24 @@
+import { type LoaderFunctionArgs } from "@remix-run/server-runtime";
+import { redirect } from "~/services/no-store-redirect";
+import { builderUrl } from "~/shared/router-utils";
+
+// Support for Auth Token URLs generated by previous Builder versions
+// @todo: Remove after 2024-12-31
+export const loader = async ({ request, params }: LoaderFunctionArgs) => {
+  if (params.projectId === undefined) {
+    throw new Response("projectId is required", {
+      status: 404,
+    });
+  }
+
+  const url = new URL(request.url);
+
+  return redirect(
+    builderUrl({
+      projectId: params.projectId,
+      origin: request.url,
+      authToken: url.searchParams.get("authToken") ?? undefined,
+      mode: url.searchParams.get("mode") === "preview" ? "preview" : "design",
+    })
+  );
+};