Serial logs overwrite previous lines in WindTerm

When viewing serial logs in WindTerm, some lines overwrite the previous line instead of appending.
The issue happens because the logs include ESC]104 sequences. WindTerm doesn’t parse these sequences, so it moves the cursor to the start of the line and overwrites existing text.

Start by locating the C terminal escape-sequence handling for ESC]104 and reproduce the overwrite with the serial-log example. The work is done when those sequences no longer move the cursor to the line start or overwrite previously displayed log text.

Written by the indexing model from the issue text.