A machine that arrives as a value can still be commanded, so a name may name its state (#58)

Set state and State branch derived their ports from the graph, so a machine
that came out of a variable or a list had no ports at all: nothing to set,
nowhere to branch. It could be passed around but not operated.

stateByName() resolves id first, then name; a name two states carry answers
with nothing, the same rule transitionTo already follows for two transitions
of one name — without something in the graph that decides between them, any
pick would be a guess.

Set state by name takes the machine and a text, and has a second exec output
not found, so a typo is not swallowed in silence. State branch gains a
derived else that fires whenever no state output matches — no state set, a
state of another machine, or a machine that arrives as a value and therefore
has no state outputs at all. A flow that enters State branch now always
leaves it somewhere.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/core/graph/nodes/index.ts

@@ -97,6 +97,7 @@ import { Repeat } from './flow/Repeat';
 import { RunBehavior } from './flow/RunBehavior';
 import { Sequence } from './flow/Sequence';
 import { SetState } from './flow/SetState';
+import { SetStateByName } from './flow/SetStateByName';
 import { StateBranch } from './flow/StateBranch';
 import { StateTransition } from './flow/StateTransition';
 import { PARTICLE_NODES } from '../../particles/nodes';
@@ -132,6 +133,7 @@ export const BUILT_IN_NODES: readonly NodeDef[] = [
   RunBehavior,
   StateBranch,
   SetState,
+  SetStateByName,
   StateTransition,
   CurrentState,
   IsInState,