A behavior node that cannot run looked exactly like a healthy one: no start node, no behavior picked, a deleted behavior or a self-call were all silently skipped. The call still had to be forgiving at runtime -- a dangling reference must not abort a game -- so the fix is diagnosis, not an exception: describeProblem() names the one reason, the node draws it in red under its title, and the inspector repeats it where you pick the behavior. A missing end node is deliberately not a problem: a call is always synchronous, and the end node only decides which values come back. Two ways in: a behavior dragged from the asset panel lands in the graph under the pointer, and double-clicking a call node opens the graph it runs. Both reuse machinery that already existed -- the asset panel already starts the drag, and list views already report double clicks. The e2e module needed its assets at the head of the asset list: after 18 modules the list is long enough that a newly appended row scrolls out of view, and the press then lands on the panel behind it, starting no drag at all. That looked exactly like a rejected drop and cost two full runs. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
todo-notes
A drop box for ideas that come up while work is already in progress, so they are not lost and not squeezed into the running task. One file per topic, free form, any language.
Anything in here is fair game to pick up at any time. When a note is done, move the file to done/
rather than deleting it – the note says what was wanted, the commit says what was built.