Addresses the testing feedback on the conductor selection-properties
prototype:
1. Edits were never applied. The dock drives every editor through
setLiveEdit(true), which each editor overrides to connect its field
changes to apply(); ConductorPropertiesEditorWidget didn't override it,
so the call was a no-op. Implement setLiveEdit() to connect the hosted
ConductorPropertiesWidget's controls (commit-style signals) to apply().
A m_updating guard suppresses the signals emitted while the widget is
loaded programmatically, so a partial mid-load state is never committed.
2. Clicking a conductor's text label showed nothing, because the label is
a ConductorTextItem, not a Conductor. Map it to its parentConductor() in
the editor factory, mirroring the double-click-the-label dialog behaviour.
3. The panel sat at a small size hint with empty space below it. Give the
editor an Expanding vertical size policy (and a minimum height) so it
fills the dock like the other editors.
Refs #500
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Shane Ringrose