image_gen output no longer saved to accessible local path

Regression in recent Codex Desktop versions: image_gen output is rendered in the UI but is no longer saved under ~/.codex/generated_images/<thread_id>/, and the agent cannot access a filesystem path for the generated artifact.

This used to work. Existing historical files are still present under ~/.codex/generated_images/<old_thread_id>/, with last modified times around Jun 11 / May 22. However, newly generated images do not appear under ~/.codex/generated_images or any recent ~/.codex image path.

Impact: workflows that generate Image 2.0 diagrams and then commit them into a repo are broken. The only workaround is manually downloading the image from the UI to ~/Downloads and asking the agent to copy it into the workspace.

Codex version: 26.611.62324