Background sessions take over a worktree under different conditions

A background session is a Claude Code session that runs without being attached to your terminal. A worktree is a separate working copy of a git repository. When a background session starts, it can adopt, or take over, a worktree.

It previously did nothing if no worktree path had been saved. It no longer needs a saved path. It adopts a worktree only when it starts inside a matching worktree layout, and a further check can stop the adoption.