AGENTS.md requires shallowRef by default. All test state uses
reassignment (not mutation), so shallowRef is correct.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Provides render() for integration testing — async with auto-flush,
trimmed frames, fake terminal with resize(), stdin.write() with
auto-flush, and auto-cleanup via afterEach.
Exports: render, cleanup, RenderResult, RenderOptions, Terminal
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Yunfei He