Entry.Completed accidentally fired on Enter key press in the 'Conversion candidate window' in Chinese/Japanese IME #36179

/// <summary>
/// Platform-level IME tracking flag: Set to true immediately after the IME finishes text composition
/// (e.g. pressing Enter to confirm/cancel Chinese input, or pressing Enter to finalize Japanese conversion).
/// This flag suppresses the subsequent Completed event to prevent treating the Enter key for candidate confirmation as a send command by mistake.
/// </summary>
private bool _imeCompositionJustEnded;

public AssistanceChatView(Guid? sessionId, Func<IEnumerable<AIFunction>>? aIFunctionsFactory = null, string? projectPath = null, string? projectName = null)
{
    InitializeComponent();
    //...

    // Hook up IME composition state tracking after the native control is created, to prevent
    // accidental message sending when pressing Enter to confirm candidate words in Chinese/Japanese IMEs
    TestEntry.HandlerChanged += EntryHandlerChanged;

    TestEntry.Completed += EntryCompleted;
}

private void EntryHandlerChanged(object? sender, EventArgs e)
{
#if WINDOWS
    if (AIInputButton.Handler?.PlatformView is Microsoft.UI.Xaml.Controls.TextBox textBox)
    {
        // Triggered when IME starts composition (e.g. typing Pinyin for Chinese, typing Kana for Japanese)
        textBox.TextCompositionStarted += (_, _) =>
        {
            _imeCompositionJustEnded = false;
        };

        // Triggered when IME finishes composition (user presses Enter to confirm/cancel candidates, or clicks candidate words with mouse, etc.)
        textBox.TextCompositionEnded += (_, _) =>
        {
            _imeCompositionJustEnded = true;

            // Clear the flag in the next idle UI cycle (Low priority).
            // This ensures the Completed event can still read the true flag within the current message loop.
            // If composition ends for reasons other than pressing Enter, the flag will also be cleared quickly
            // without interfering with subsequent genuine send operations.
            textBox.DispatcherQueue?.TryEnqueue(
                Microsoft.UI.Dispatching.DispatcherQueuePriority.Low,
                () => _imeCompositionJustEnded = false);
        };
    }
#endif
}

private async void EntryCompleted(object? sender, EventArgs e)
{
    // Ignore this Completed event and skip message sending if the Enter keystroke came from IME candidate confirmation / composition cancellation (Chinese / Japanese IMEs)
    if (_imeCompositionJustEnded)
    {
        _imeCompositionJustEnded = false;
        return;
    }

    DoAction();
}

void DoAction()
{
    //...
}