This PR merges and dedupes sequential exec cells so they stack neatly on sequential lines rather than separate blocks. This is particularly useful because the model will often sed 200 lines of a file multiple times in a row and this nicely collapses them. https://github.com/user-attachments/assets/04cccda5-e2ba-4a97-a613-4547587aa15c Part 1: https://github.com/openai/codex/pull/2095 Part 2: https://github.com/openai/codex/pull/2097