[Bug] REPL cat() command fails to extract text or image from PDF files

Question

**Bug Description**
Gave CLAUDE_CODE_REPL a try - cat() cannot properly read/render PDFs with poppler like Read tool can. Kinda makes sense if any output is supposed to be plain text for piping. You probably want to keep the Read tool available to the model and have instructions say prefer reading PDFs with Read.

Separately, even if not for image extraction / rendering, cat() needs to be fixed to at least allow text extraction from PDFs. It currently returns empty string no matter what, per Cla