The reported "cannot add edges" has a specific cause: the output port's hit
radius reaches past the box it belongs to, and the press handler re-derives the
owning node with a box test, so clicking the visible dot's outer half sets
pending_out to -1 and silently disarms. Edge deletion has no code path at all.
The design replaces the two-click protocol with a drag gesture, makes the list
order the editor's own invariant via a topological re-sort rather than a rule the
user must obey, adds a view transform with every hit test routed through its
inverse, and trades the modal alert on Apply for a live validation line. It also
records that the Cancel button still calls gtk_window_destroy -- the dangling
dialog pointer CLAUDE.md documents as fixed was only fixed on the Apply path.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>