The chain read as a loose list: a redundant title, dot-and-line timeline
ornament, muted values that were hard to scan, and raw setting values
("worktree", "local"). It is now one compact card per environment, headed
by the machine icon and name, with three aligned rows (Project, Environment,
Default) and the winning row highlighted; values use the same labels as the
controls and unset layers read Inherits.

Providers and Diagnostics get their project crumb back. The project axis
does not gate the page; it narrows which environments the page can show,
which is useful when a project lives on one machine.