Visual redesign of "Add Node"

Running plugins and pipelines is the quintessential feature of _ChRIS_, yet currently (according to user reports) it is not obvious how to do this in _ChRIS\_ui_. Currently, the user must right-click a selected "node" to show a context menu from where "Add a node" or "Add a pipeline" can be selected.

Below is a mock-up of what a visual redesign might look like, replacing text boxes with interactive visual widgets. Here, a grey-ed out child node appears below the selected node when the mouse is nearby (i.e. inside the graph view quadrant). The proposed design is more discoverable at-a-glance.


Start by reviewing the ChRIS_ui graph-view implementation and the existing “Add a node” and “Add a pipeline” context-menu entry points. Compare the current interaction with the linked mock-up, then clarify the visual behavior and acceptance criteria before implementation; done means the redesign is implemented and the add-node and add-pipeline actions remain usable.

Written by the indexing model from the issue text.