Numeric dependsOn values (merge-type variations) are RFC edge values,
not ATTR names. Display them as the number, not as "ATTR: N" or
"subvariation N".
PaneCP: replace horizontal breadcrumb with vertical list of short views
for each node in the focus path (type tag + label/identifier). Clicking
any item above current navigates up.
PaneFO: show score info fields (title, composer, source, encrypter) as
editable DL when at score level instead of 'Nothing selected'.
AppShell already wraps each component in div.se-pane; the inner se-pane
had display:none without .active, hiding all content.
Also drop stale movement/part/line/measure bar fields (bar IDs are opaque).