refactor: use shared component for login callback pages

frontend/src/lib/api/responses.ts

@@ -0,0 +1,23 @@
+import type { MeUser } from "./entities";
+
+export interface SignupResponse {
+  user: MeUser;
+  token: string;
+}
+
+export interface MetaResponse {
+  git_repository: string;
+  git_commit: string;
+  users: number;
+  members: number;
+  require_invite: boolean;
+}
+
+export interface UrlsResponse {
+  discord: string;
+}
+
+export interface ExportResponse {
+  path: string;
+  created_at: string;
+}