Huge resolution GIF

I'm rendering a very short session (under 200 frames), which results in a massive 15mb GIF with a resolution of 1552x920.

I can post-process the file using `gifsicle` and significantly reduce its size, but scaling it makes the text blurry no matter the filter.

It would be nice if I was able to specify the rendering size in the first place.

No file or test is named in the issue. Start by tracing the terminalizer rendering entry point and its existing configuration options; define completion as an input that controls output GIF dimensions without requiring post-processing, then verify it on a short recording.

Written by the indexing model from the issue text.