Use a dedicated --text-on-accent token for accent chips/checkmarks and tweak task list item surfaces so task/todo renderers keep contrast in dark mode.
Use tokenized border contrast so dark mode borders stay subtle, keep instance tab status dots vivid in dark themes, and adjust tool-call code block header background via a dedicated token.
Add a 3-state theme toggle in folder selection and instance tabs, and update tokens/styles so light mode has readable contrast. Sync MUI surfaces and Shiki highlighting to CSS variables to prevent stale colors when switching themes.
Show sessions as parent/child threads with expand/collapse and improved agent row styling. Keep a 5-session cache to avoid refetching messages when switching between recently visited sessions.
