Add authenticated login and SSO protection

lib/server/api.ts

@@ -5,9 +5,10 @@ export function jsonOk<T>(payload: T, init?: ResponseInit) {
 }
 
 export function jsonError(error: unknown, status = 400) {
+  const resolvedStatus = statusFromError(error) || status;
   return NextResponse.json({
     error: error instanceof Error ? error.message : String(error)
-  }, { status });
+  }, { status: resolvedStatus });
 }
 
 export async function readJsonBody<T extends Record<string, unknown>>(request: Request): Promise<T> {
@@ -17,3 +18,9 @@ export async function readJsonBody<T extends Record<string, unknown>>(request: R
     return {} as T;
   }
 }
+
+function statusFromError(error: unknown): number | undefined {
+  if (typeof error !== "object" || error === null || !("status" in error)) return undefined;
+  const status = Number((error as { status?: unknown }).status);
+  return Number.isInteger(status) && status >= 400 && status <= 599 ? status : undefined;
+}