A transition carries a name, so a state needs no visible port (#52)

A state keeps its `in`/`out` exec pins in the model and the editor never draws
them. That is the whole trick: connecting, undo, deleting a state and saving all
keep working untouched, because `normalizeGraph` filters nodes and never edges,
and no edge ever checks its port key against a NodeDef. Only two places change --
`NodeView.redraw` stops drawing the row, and `portAt` refuses to hand one out, so
an invisible pin cannot be grabbed either.

Transitions are drawn by right-clicking a state, `Make transition`, then clicking
the target. The armed mode takes the same shape as a live drag, so the existing
preview draws it with no second code path, and it dies with Escape, a click on
empty canvas or a switch to another asset.

Removing the pins removed the only handle a transition had: edges have no
hit-test anywhere, and the pin right-click was the sole route to Disconnect.
The inspector's TRANSITIONS OUT / TRANSITIONS IN lists are therefore not a
convenience, they are the delete path.

`GraphEdge` gained an optional `label`, which `normalizeGraph` has to pass
through explicitly or a saved name is dropped on load. `State transition`
replaces `Next state`: it takes the machine on an input port and the name from a
picker, and resolves against the *current* state. Names are deliberately not
unique across a machine -- two states may both have an `alarm` -- so a node named
`alarm` moves whichever state has one, and an empty name follows the single
unnamed edge.

The geometry moved to a Pixi-free `transitions.ts`: a gap to the box border, and
a fan that puts a pair of opposite edges beside each other instead of on top of
each other. Keeping it as plain maths is what let a screenshot bug become a unit
test -- an earlier pin-to-pin line ran under the target node and took its
arrowhead with it, because `nodeLayer` sits above `edgeLayer`.

One limit stands and is not fixed here: `ConnectCommand` rejects a second edge
between the same two states ("Already connected"), because every transition
hangs off the same two ports. With names, `A --alarm--> B` beside
`A --seen--> B` is a sensible pair, so this is worth its own issue.

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

src/editor/debugHook.ts

@@ -1,4 +1,5 @@
 import { type Application, Color, type ColorSource, type Container, Mesh, Rectangle, Text } from 'pixi.js';
+import { NameTransitionCommand } from '../core/commands/graphCommands';
 import { resolveObjects } from '../core/model/instance';
 import { findObjectHolder } from '../core/model/Project';
 import type { FrameRect } from '../core/model/texture';
@@ -287,6 +288,21 @@ export function installDebugHook(app: Application, state: EditorState, editor: E
       canvasRect: () => editor.stateMachineEditor.canvas.canvasRect(),
       center: () => centreOf(editor.stateMachineEditor.canvas),
       snapping: () => editor.stateMachineEditor.canvas.snapEnabled,
+      /** Where a state's hidden pin sits. It is no longer grabbable – `portGrabbable` is the check. */
+      portAt: (nodeId: string, port: string, isOutput: boolean) =>
+        editor.stateMachineEditor.canvas.portGlobal(nodeId, port, isOutput),
+      portGrabbable: (nodeId: string, port: string, isOutput: boolean) =>
+        editor.stateMachineEditor.canvas.portGrabbable(nodeId, port, isOutput),
+      edgeDrawn: (edgeId: string) => editor.stateMachineEditor.canvas.edgeDrawn(edgeId),
+      transitionLabel: (edgeId: string) => editor.stateMachineEditor.canvas.transitionLabelDrawn(edgeId),
+      hint: () => editor.stateMachineEditor.canvas.shownHint(),
+      /** Names a transition the way the inspector row does, for steps that need one already named. */
+      nameTransition: (edgeId: string, name: string) =>
+        state.execute(new NameTransitionCommand(editor.stateMachineEditor.currentAssetId, edgeId, name)),
+      dropTarget: () => editor.stateMachineEditor.canvas.pendingDropTarget(),
+      danglingEdge: () => editor.stateMachineEditor.canvas.danglingEdgeVisible(),
+      emptySpot: () => editor.stateMachineEditor.canvas.emptySpotGlobal(),
+      selected: () => state.selectedNodeIds,
     },
     particles: {
       current: () => editor.particlesEditor.currentAssetId,