Error when entering part of a two-byte symbol

### Prerequisites - [x] Write a descriptive title. - [x] Make sure you are able to repro it on the [latest released version](https://www.powershellgallery.com/packages/PSReadLine) - [x] Search the existing issues, especially the pinned issues. ### Exception report ```console ### Environment PSReadLine: 2.4.5 PowerShell: 7.6.1 OS: Microsoft Windows 10.0.26100 BufferWidth: 102 BufferHeight: 51 Last 102 Keys: s t a r h s i Backspace Backspace Backspace h Backspace s h i p Spacebar e x p l a i n Enter Backspace  Enter \ u f 1 8 8 Enter e c g Backspace h o Spacebar \ u f 1 8 8 Enter e c g i Spacebar Backspace Backspace Backspace h o Spacebar  Enter e c h o Spacebar � � Enter e c h o Spacebar  Enter e c h o Spacebar � � Enter e c h o Spacebar � � Backspace Backspace Backspace Spacebar � � Enter UpArrow Backspace Enter ### Exception System.Text.EncoderFallbackException: Unable to translate Unicode character \\uDB82 at index 5 to specified code page. at System.Text.EncoderExceptionFallbackBuffer.Fallback(Char charUnknown, Int32 index) at System.Text.Encoding.GetBytesWithFallback(ReadOnlySpan`1 chars, Int32 originalCharsLength, Span`1 bytes, Int32 originalBytesLength, EncoderNLS encoder, Boolean throwForDestinationOverflow) at System.Text.Encoding.GetBytesWithFallback(Char* pOriginalChars, Int32 originalCharCount, Byte* pOriginalBytes, Int32 originalByteCount, Int32 charsConsumedSoFar, Int32 bytesWrittenSoFar, EncoderNLS encoder) at System.IO.StreamWriter.Flush(Boolean flushStream, Boolean flushEncoder) at System.IO.StreamWriter.Dispose(Boolean disposing) at System.IO.TextWriter.Dispose() at Microsoft.PowerShell.PSConsoleReadLine.<>c__DisplayClass104_0.<WriteHistoryRange>b__0() at Microsoft.PowerShell.PSConsoleReadLine.<>c__DisplayClass104_0.<WriteHistoryRange>b__0() at Microsoft.PowerShell.PSConsoleReadLine.WithHistoryFileMutexDo(Int32 timeout, Action action) at Microsoft.PowerShell.PSConsoleReadLine.WriteHistoryRange(Int32 start, Int32 end, Boolean overwritten) at Microsoft.PowerShell.PSConsoleReadLine.IncrementalHistoryWrite() at Microsoft.PowerShell.PSConsoleReadLine.MaybeAddToHistory(String result, List`1 edits, Int32 undoEditIndex, Boolean fromDifferentSession, Boolean fromInitialRead) at Microsoft.PowerShell.PSConsoleReadLine.InputLoop() at Microsoft.PowerShell.PSConsoleReadLine.ReadLine(Runspace runspace, EngineIntrinsics engineIntrinsics, CancellationToken cancellationToken, Nullable`1 lastRunStatus) ``` ### Screenshot <img width="930" height="208" alt="Image" src="https://github.com/user-attachments/assets/a05e139b-c25d-49ca-b302-c9f45b29881a" /> ### Environment data ```console PS Version: 7.6.1 PS HostName: ConsoleHost (Windows Terminal) PSReadLine Version: 2.4.5 PSReadLine EditMode: Windows OS: 10.0.26100.1 (WinBuild.160101.0800) BufferWidth: 102 BufferHeight: 51 ``` ### Steps to reproduce 1. Write `echo 󰨰` in the terminal. The character code is `\udb82\ude30` 2. Press up and delete the second char of the two byte symbol. 3. Crash. ### Expected behavior No crash. ### Actual behavior Crash.