## Summary
This PR builds _heavily_ on the work from @occurrent in #8021 - I've
only added a small fix, added additional tests, and propagated the
changes to tui2.
From the original PR:
> On Windows, Codex relies on PasteBurst for paste detection because
bracketed paste is not reliably available via crossterm.
>
> When pasted content starts with non-ASCII characters, input is routed
through handle_non_ascii_char, which bypasses the normal paste burst
logic. This change extends the paste burst window for that path, which
should ensure that Enter is correctly grouped as part of the paste.
## Testing
- [x] tested locally cross-platform
- [x] added regression tests
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Co-authored-by: occur <occurring@outlook.com>
0f8bb4579b