Reattaching to a background session can stop retrying, and exit waits briefly

A background session is a Claude Code session that keeps running after you leave it, and you can attach to it again later. When the connection drops, Claude Code tries to reconnect in a loop. That loop now checks whether it should stand down, at the start of each try and when the background process fails to start. If so, it stops without the "Couldn't restart" error. It can also report that it detached before the first screen was drawn.

When Claude Code shuts down, it now waits for the attached session to settle before exiting, for at most 5 seconds.