Improve visual distinction between Projects and Threads in Codex Desktop sidebar

Feedback

In Codex Desktop, the sidebar entries for projects/folders and individual threads look too similar. The folder icon plus project name and the thread title have nearly the same visual weight, so when many projects and threads are present it is easy to misread the navigation list or click the wrong item.

Suggested improvements

• Add stronger visual hierarchy between project rows and thread rows.
• Give project rows a distinct background, left color bar, icon accent, or section treatment.
• Allow separate colors/highlights for project names and thread titles.
• Keep the current compact layout, but make project/thread boundaries easier to scan.

Why it matters

For users managing many long-running Codex projects and threads, the sidebar is a primary work surface. Clear project/thread distinction would reduce navigation mistakes and improve readability without changing the workflow model.