StudyGraphEditor

The study composer's Model section, as a graph.

In the namespace study::ui. Declared in src/libs/libstudy/study/ui/StudyGraphEditor.hpp.

Detailed description

construct-project-space P13, §PSU-6. This replaces the `QTreeWidget` that listed components and their ports. The tree is not deleted — it moves to a second tab — because the two answer different questions: the graph shows the SHAPE and the tree shows the DETAIL, and a port's unit is not readable off a box.

What it shows without being asked

§PSU-1: never show a number without its status. The status line under the canvas reports the component count, the connection count and **how many configuration problems `ModelGraph::validate()` found**. A composer that drew a tidy graph and said nothing about it being invalid would be the exact failure that rule exists to prevent.