"Set for all..." made a differing value look like a mode: press it and a
select appeared with a value that was not among its options. Controls now
follow the multi-selection inspector convention: the real select, input,
switch or model picker stays in place with Mixed as its placeholder, and
choosing a value applies it to every selected environment. Switches get a
centred-thumb mixed state that turns on for everyone when clicked. The
writing-style row checks each field on its own, so differing template
preferences no longer turn the instructions editor into a bulk draft.

Providers and Diagnostics no longer interrupt with a pick-an-environment
notice: they are per machine, so their breadcrumb ends at the environment
crumb and they open on the representative environment. The scope crumbs
drop the hover chevron and its reserved gap. Non-server rows stop inheriting
the summary caption that the layers icon already carries.