Chats keep working after a save error, and old broken ones heal
A chat whose step could not be saved keeps going, cut-off chats open fine again, and a resumed side session no longer fails when its chat is busy.
If a step's result could not be written to disk, the chat used to refuse every later message. It now marks that one step as not saved and carries on, and the same thing happens when you reopen it. Chats that were already stuck this way heal when you open them.
Watching a background run no longer shows its running tools as failed. A side session that you resume while its chat is mid-turn now waits for a free slot instead of failing.