File session-transcript.test.ts

packages/core/src/__tests__/session-transcript.test.ts:None–None

import { describe, expect, it, beforeEach, afterEach } from "vitest";
import { mkdtemp, rm, readFile, mkdir, writeFile } from "node:fs/promises";
import { join } from "node:path";
import { tmpdir } from "node:os";