[Bug]: Chrome + IME: Enter key causes text duplication in TldrawUiInput component
### What happened?

The issue I encountered is that in Chrome, using the Chinese input method, pressing the Enter key while inputting in the TldrawUiInput component causes text to be duplicated.

As shown in the gif below, my key sequence is `a` → `Enter`. The expected behavior should be that the input method exits and inputs the letter `a`, but the actual effect is that two `a` are entered.

![Image](https://github.com/user-attachments/assets/a8a03652-18b8-47b9-9fcd-f97f671bd582)

I have three different browsers on my computer: Chrome, Safari, and Zen. After testing, I found that only Chrome has this issue, which may be related to its internal event logic handling.

I found that the reason for this issue is that in Chrome, if `e.currentTarget.blur()` is executed in the `<input>`'s `onKeyDownCapture`, it will trigger an incorrect `onChange` event with duplicate text data when the input method exits.

By listening to the [composition event](https://developer.mozilla.org/en-US/docs/Web/API/CompositionEvent), it can be determined whether the current `Enter` was pressed during IME execution, thus avoiding this issue.

### How can we reproduce the bug?

_No response_

### What browsers are you seeing the problem on?

Chrome

### Where did this happen?

The tldraw.com website

### Contact Details

_No response_

### Code of Conduct

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