Projects
A project groups chats around a working directory: it can hold one or more
project workspaces (folders, repos, or worktrees), has its own artifact
rendering, and can carry a startup mode governing how new chats in it start
from those workspaces. A project's active state (in the Projects nav view)
is distinct from an archived project (a Settings surface — see
references/settings.md); don't conflate the two when a user asks where a
project went. Source lives in src/features/projects/; verify current
workspace/startup-mode behavior there, since this has direct interaction
with git worktrees and can change.