Clickable "ghost" nodes for non-broadcast project nodes

### Description

For reasons of clarity and comprehensibility we'd like to have clickable ghost nodes - like the ones regular link nodes have - for project nodes that don't send or receive broadcasts:

This would greatly improve comprehensibility of flows which heavily rely on project nodes.

### Requested By

Start by locating the project-node rendering and the existing ghost-node behavior for regular link nodes. Compare how non-broadcast project nodes are represented, then verify that these nodes display clickable ghost nodes and that flows relying on project nodes are clearer to navigate.

Written by the indexing model from the issue text.