Ports that vary per node already existed, but only for the three nested-behavior
types, and the rule for them sat as a switch on type names in nested.ts – the
one place in the project that knew node types by name. It dissolves into two
optional contracts on NodeDef, so a type carries its own rule:
declaresPorts the node holds an editable list, shown as a section in the
inspector – behavior start/end, and now Pack/Expand
derivePorts the node computes them from its settings – Sequence from a
count, Run behavior from the behavior it names
Sequence gains an Outputs setting (2 to 26). Its keys stay a, b, c and count on
with d, e, so the edges of the sequences already out there survive.
A param can now take a port away, and the edge on it would stay: it draws as
nothing yet survives every save, and comes back to life if the port returns.
SetNodeParamCommand takes those edges with it, which also closes the same leak
that switching a Run behavior node's target has always had.
The port editor addresses its node by id rather than by type, so two Pack nodes
can live in one graph, and it calls the rows Fields when they are not a
behavior's signature.
A behavior that has a Start and an End node can now be dropped into any
other graph as a node of its own. What is declared on the start node
becomes the inputs of that node, what hangs on the end node its outputs;
the port list is derived from the sub graph, not copied, so declaring a
port in one graph grows the node in the other without touching it. The
node carries the behavior's name and the palette lists behaviors by
name, so a call is one grab instead of a node plus a dropdown.
An embedded behavior has no object and therefore no place for
variables: every call starts on the asset defaults and communicates
only through its ports. That is the conservative direction - state can
still be added later, and shared state already has a home in a behavior
object in the scene. Node ids are unique per graph only, so each call
gets its own pulse cache; without that, two graphs would collide.
Renaming a port used to silently drop the value typed on the calling
node. It is carried along now, project wide, like the edges.