Controls committed on blur, which turned leaving a field into a durable,
revision-fenced document write the user could neither preview nor undo, and
silently discarded a draft the field did not accept.
A card's form now owns the staged text every control renders, and Save is the
only point where drafts become writes. Reset stages the composed default the
same way; an invalid draft blocks the save with its reason instead of being
dropped; Discard drops the drafts; a collapsed card marks that it holds some.
The Host stays the only authority on whether a value was accepted, so the save
reads the section back and keeps the drafts of a save that did not land.
The section knows no namespace: it declares `settings.plugin.item` and
renders whatever cards were registered into it, so a plugin that ships a
browser half owns its card and its controls. The three cards here cover the
host-plane sections this deployment exposes.
A field shows its effective value and, when the raw user layer carries it, an
override badge and a reset that clears it back to the composition layer.
Controls commit on blur and Enter rather than per keystroke, which would burn
namespace revisions and race its own reads. The search key is the one value
that never rides a response: the card reports only whether one is configured
and writes it through the credentials domain, addressed by the reference the
section names.
A card renders nothing while its namespace is unavailable — a deployment that
does not compose the owning plugin should show no trace of it rather than a
disabled card the user cannot act on.
