Add support for terminal bounds

We should support some option to specify the `columns` and `rows` of the imaginary terminal.

This way, things like `ESC D` actually chops off the top line instead.

im not sure yet if it should _remove_ the line, or keep it in a cache somewhere in case you scroll back. need to read up on this again.

Look at the library's handling of terminal escape sequences, particularly ESC D (index). The issue mentions needing to read up on terminal behavior for line chopping and scrollback caching. Start by examining the code that processes ANSI sequences and manages the terminal buffer. Determine where columns and rows configuration would be added and how line removal or caching should be implemented.

Written by the indexing model from the issue text.