Avoid synthetic-input bugs in automation targeting IME-based (CJK) text entry by respecting composition events instead of raw keydown

Steps

1. Recognize that typing CJK text involves a distinct composition phase — compositionstart/compositionupdate/compositionend fire around the eventual final input event, not a simple keydown/keyup per character
2. When scripting Enter-key handling for an app under test, check the event's isComposing flag before treating Enter as a submit/select action, since an IME Enter often confirms a candidate rather than submitting
3. In frameworks with synthetic event systems (e.g. React), read isComposing off the native event rather than the synthetic wrapper, since the synthetic event may not carry it
4. When driving automation input synthetically, prefer setting the input value plus dispatching input/composition events over simulating raw per-character key presses, since most automation keyboard APIs type Latin characters without a real IME composition sequence
5. Test with an actual non-Latin locale/keyboard layout in CI rather than assuming Latin-keyboard automation coverage generalizes, since physical key codes are layout-dependent