opstool v1.0.26 (GPL-3.0) is cloned read-only under
.slim/clonedeps/repos/ to inspect its PyVista/Plotly visualization
settings. GPLv3 section 13 permits combining it with this AGPL-3.0
project. The clone itself is git-ignored; the manifest and the AGENTS.md
pointer are committed.
Both backends share one SelectionState owned by MainWindow and live
side by side in a QStackedWidget — switching is setCurrentWidget, so
no widget is destroyed mid-session (tearing a VTK window down leaves
dangling make-current callbacks). The choice persists in QSettings.
CanvasCapabilities declares per-backend gaps (force diagrams and
video export stay PyVista-only, both are documented and greyed out)
and the UI gates on capabilities rather than the backend name. The
architecture gate now allows the canvas_plotly package.
