Backspacing on second line into first line causes typing test to break

When wanting to delete characters from the first line while in the second it cause Typr to break.

How to recreate:

1. Start Typr
2. Complete the test until on the second line
3. Backspace / Delete characters until the cursor is moved up to the first line

<img width="926" height="332" alt="Image" src="https://github.com/user-attachments/assets/36afa046-7994-4182-8ee2-535c9d2ef2de" />