PageScene: move change_mode + toggleTransformSpace into GizmoController

GizmoController now reads/writes the store's transformSpace through a
new GizmoControllerDeps surface that Editor wires up in initialize().

- changeMode(type) reads the desired space from the store internally
  (forces local for scale), so callers don't plumb space through.
- toggleTransformSpace() owns the read/flip/write/apply loop that used
  to live on Editor.toggleTransformSpace.

Editor.change_mode and Editor.toggleTransformSpace are deleted.

Callers updated:
- actions/setTransformMode.ts → editor.gizmo.changeMode(...)
- Controls3D.tsx → editorEngine?.gizmo.toggleTransformSpace()
- keymap.ts → editor.gizmo.changeMode + .toggleTransformSpace; the
  inline setGizmoMode body shrinks to one line and the duplicate
  toggleTransformSpace helper is gone.

frontend/apps/artcraft/app/src/pages/PageScene/actions/setTransformMode.ts

@@ -8,7 +8,7 @@ const ENGINE_MODE: Record<TransformMode, "translate" | "rotate" | "scale"> = {
 };
 
 export function setTransformMode(editor: Editor, mode: TransformMode): void {
-  editor.change_mode(ENGINE_MODE[mode]);
+  editor.gizmo.changeMode(ENGINE_MODE[mode]);
   const store = usePageSceneStore.getState();
   store.setTransformMode(mode);
   store.setSelectedMode(mode);

frontend/apps/artcraft/app/src/pages/PageScene/comps/Controls3D/Controls3D.tsx

@@ -318,7 +318,7 @@ export const Controls3D = () => {
               >
                 <button
                   className="h-9 rounded-[10px] px-2.5 text-[10px] font-semibold font-mono bg-white/15 hover:bg-white/25 transition-colors uppercase tracking-wide"
-                  onClick={() => editorEngine?.toggleTransformSpace()}
+                  onClick={() => editorEngine?.gizmo.toggleTransformSpace()}
                 >
                   {transformSpace === "world" ? "World" : "Local"}
                 </button>

frontend/apps/artcraft/app/src/pages/PageScene/engine/editor.ts

@@ -136,7 +136,11 @@ class Editor {
     // PostProcessingPipeline must exist before Scene because Scene's
     // load paths invoke updateSurfaceIdAttributeToMesh as a callback.
     this.postProcessing = new PostProcessingPipeline();
-    this.gizmo = new GizmoController();
+    this.gizmo = new GizmoController({
+      getTransformSpace: () => usePageSceneStore.getState().transformSpace,
+      setTransformSpace: (space) =>
+        usePageSceneStore.getState().setTransformSpace(space),
+    });
     this.cameraController = new CameraController({
       getThreeScene: () => this.activeScene.scene,
       getHotItems: () => this.activeScene.hot_items ?? null,
@@ -823,24 +827,6 @@ class Editor {
     console.log("3D Editor Engine unmounted");
   }
 
-  // Facade for actions/setTransformMode + keymap dispatch. Reads the
-  // store's current transform space and forwards to the gizmo.
-  change_mode(type: "translate" | "rotate" | "scale") {
-    const space =
-      type === "scale" ? "local" : usePageSceneStore.getState().transformSpace;
-    this.gizmo.changeMode(type, space);
-  }
-
-  // Facade for Controls3D button + keymap. Toggles the store's
-  // transform space and pushes the new value into the gizmo.
-  toggleTransformSpace() {
-    if (!this.gizmo.canToggleSpace()) return;
-    const store = usePageSceneStore.getState();
-    const next = store.transformSpace === "world" ? "local" : "world";
-    store.setTransformSpace(next);
-    this.gizmo.setSpace(next);
-  }
-
   // Facades — external callers in actions/* and helper.ts target these
   // names. Internals reach the bridge directly via this.selection.*.
   updateOutliner() {

frontend/apps/artcraft/app/src/pages/PageScene/engine/editor/GizmoController.ts

@@ -4,9 +4,8 @@
 // on Editor), then `configure()` wires it to the camera/renderer once
 // initialize() has produced them.
 //
-// No `editor` reference, no `import type Editor`. Store access stays on
-// Editor's facades (change_mode, toggleTransformSpace); this module only
-// translates them into TransformControls calls.
+// Store access for the transform-space pref is injected via Deps so the
+// controller doesn't import the Zustand store directly.
 
 import type * as THREE from "three";
 import { TransformControls } from "../TransformControls.js";
@@ -22,9 +21,23 @@ export type GizmoCallbacks = {
   onDraggingChanged: (dragging: boolean) => void;
 };
 
+// Capabilities the gizmo needs from outside its own state.
+// Editor wires these in initialize() so GizmoController never imports
+// the store directly.
+export type GizmoControllerDeps = {
+  getTransformSpace: () => TransformSpace;
+  setTransformSpace: (space: TransformSpace) => void;
+};
+
 export class GizmoController {
   control: TransformControls | undefined;
 
+  private deps: GizmoControllerDeps;
+
+  constructor(deps: GizmoControllerDeps) {
+    this.deps = deps;
+  }
+
   configure(
     camera: THREE.PerspectiveCamera | null,
     domElement: HTMLElement,
@@ -45,8 +58,11 @@ export class GizmoController {
     scene.add(this.control);
   }
 
-  changeMode(type: TransformMode, space: TransformSpace) {
+  // Apply a transform mode. Reads the desired space from the store so
+  // callers don't need to plumb it through. Scale is always local.
+  changeMode(type: TransformMode) {
     if (this.control == undefined) return;
+    const space = type === "scale" ? "local" : this.deps.getTransformSpace();
     this.control.mode = type;
     this.control.space = space;
   }
@@ -56,6 +72,17 @@ export class GizmoController {
     this.control.space = space;
   }
 
+  // Flip the store's transform-space preference and push the new value
+  // into the live gizmo. No-op when the gizmo is in scale mode (scale
+  // is always local).
+  toggleTransformSpace() {
+    if (!this.canToggleSpace()) return;
+    const next =
+      this.deps.getTransformSpace() === "world" ? "local" : "world";
+    this.deps.setTransformSpace(next);
+    this.setSpace(next);
+  }
+
   // True when the gizmo exists and is in a mode where toggling between
   // world/local space is meaningful (scale is always local).
   canToggleSpace(): boolean {

frontend/apps/artcraft/app/src/pages/PageScene/engine/keymap.ts

@@ -26,25 +26,11 @@ const setGizmoMode = (
   gizmoMode: "translate" | "rotate" | "scale",
   storeMode: "move" | "rotate" | "scale",
 ) => {
-  editor.mouse_controls?.control?.setMode(gizmoMode);
-  const space = usePageSceneStore.getState().transformSpace;
-  if (editor.mouse_controls?.control) {
-    editor.mouse_controls.control.space = space;
-  }
+  editor.gizmo.changeMode(gizmoMode);
   usePageSceneStore.getState().setTransformMode(storeMode);
   usePageSceneStore.getState().setSelectedMode(storeMode);
 };
 
-const toggleTransformSpace = (editor: Editor) => {
-  if (editor.mouse_controls?.control?.mode === "scale") return;
-  const next =
-    usePageSceneStore.getState().transformSpace === "world" ? "local" : "world";
-  usePageSceneStore.getState().setTransformSpace(next);
-  if (editor.mouse_controls?.control) {
-    editor.mouse_controls.control.space = next;
-  }
-};
-
 const deleteSelected = (editor: Editor) => {
   const mc = editor.mouse_controls;
   if (!mc?.selected) return;
@@ -108,7 +94,7 @@ export const buildKeymap = (): KeyBinding[] => [
   { code: "KeyG", label: "Scale", group: "Transform",
     run: (e) => setGizmoMode(e, "scale", "scale") },
   { code: "KeyX", label: "Toggle local/world", group: "Transform",
-    run: toggleTransformSpace },
+    run: (e) => e.gizmo.toggleTransformSpace() },
   { code: "KeyK", label: "Toggle pose (FK)", group: "Transform",
     run: (e) => e.mouse_controls?.toggleFKMode() },