refactor(core): dedupe shared config and runtime helpers

src/memory/batch-error-utils.ts

@@ -0,0 +1,23 @@
+type BatchOutputErrorLike = {
+  error?: { message?: string };
+  response?: {
+    body?: {
+      error?: { message?: string };
+    };
+  };
+};
+
+export function extractBatchErrorMessage(lines: BatchOutputErrorLike[]): string | undefined {
+  const first = lines.find((line) => line.error?.message || line.response?.body?.error);
+  return (
+    first?.error?.message ??
+    (typeof first?.response?.body?.error?.message === "string"
+      ? first?.response?.body?.error?.message
+      : undefined)
+  );
+}
+
+export function formatUnavailableBatchError(err: unknown): string | undefined {
+  const message = err instanceof Error ? err.message : String(err);
+  return message ? `error file unavailable: ${message}` : undefined;
+}