Fractional `offset` prop in `KeyboardGestureArea` causes strange overscroll behaviour

[mozzius]

Describe the bug

If using a non-integer offset in KeyboardGestureArea, there's a visual glitch when overscrolling where the sticky view is moved to completely the wrong position. This happened when we use the measured height of the text input - it started breaking when a hairlineWidth border is added. Only appears to happen on iOS, and you need to be using textInputNativeID.

Using Old Arch.

Code snippet

const [inputHeight, setInputHeight] = useState(0)

return (
  <KeyboardGestureArea
    interpolator="ios"
    offset={inputHeight} // change to `Math.round(inputHeight)` to fix
    textInputNativeID={textInputId}
    style={{flex:1}}>
      <FlatList
        // etc etc
        renderScrollComponent={renderScrollComponent} // using KeyboardChatScrollView
      />
      <KeyboardStickyView onLayout={evt => setInputHeight(evt.nativeEvent.layout.height)}>
        <MessageInput // has a hairlineWidth border
          textInputId={textInputId}
          onSendMessage={onSendMessage}
        />
      </KeyboardStickyView>
  </KeyboardGestureArea>
)

Repo for reproducing

Happy to make one if needed, but I haven't had the time to isolate it out of the bluesky repo

To Reproduce
Steps to reproduce the behavior:

1. Open chat list with KeyboardGestureArea that has a fractional offset
2. Start an interactive dismiss, then swipe it upwards to overscroll it
3. Observe the stickyview is positioned incorrectly

Expected behavior

It doesn't do that

Screenshots

Screen.Recording.2026-04-01.at.13.17.43_compressed.mp4

Smartphone (please complete the following information):

• Desktop OS: MacOS 26
• Device: iPhone 17 simulator, iOS 26.4
• OS: [e.g. iOS 10.0]
• RN version: [e.g. 0.68.2]
• RN architecture: [e.g. old/new or paper/fabric]
• JS engine: [e.g. JSC, Hermes, v8]
• Library version: [e.g. 1.2.0]

Additional context
Add any other context about the problem here.