Fix findUsages/undo/node-lookup bugs, split Viewport and Editor, share command and inspector helpers

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

src/editor/inspector/objectSection.ts

@@ -21,11 +21,12 @@ import type { Axis, PropertyValue } from '../../core/model/Properties';
 import { findAsset, findScene, type Project } from '../../core/model/Project';
 import type { SceneObject } from '../../core/model/SceneObject';
 import { COMMON_PROPS, isCommonProp, type PropertyDef, schemaForAsset } from '../../core/properties/PropertySchema';
-import { deviatesFromAsset, deviatesFromTemplate, isOverridden, resolveSceneObjectProps } from '../../core/properties/resolve';
+import { deviatesFromAsset, deviatesFromTemplate, resolveSceneObjectProps } from '../../core/properties/resolve';
 import { Button, Menu, type MenuItem, TextField } from '../../ui';
 import { addCollider, createContainer, removeObjects } from '../actions';
 import { createFieldRow, type FieldActions, type FieldRow, labelledRow } from './fieldFactory';
 import { addGap, addNote, addTitle, type InspectorHost } from './host';
+import { previewingHandlers } from './previewHandlers';
 
 const POSITION_AXES: readonly Axis[] = ['x', 'y', 'z'];
 const OFFSET_AXES = ['x', 'y'] as const;
@@ -180,32 +181,22 @@ interface ComponentSpec<V extends object> {
 
 /**
  * A number row editing one component of a vector on the object (position, editor offset).
- * Scrubbing previews straight into the model; the command is built from the value before the
- * preview so undo returns there, not to the last previewed frame.
+ * The row edits one axis, the command carries the whole vector: the other components come
+ * from the target after the preview was taken back, so they are the pre-preview ones.
  */
 function componentRow<V extends object>(host: InspectorHost, sceneId: string, objectId: string, value: number, spec: ComponentSpec<V>): void {
-  let original: V | undefined;
   const withAxis = (vector: V, next: PropertyValue): V => ({ ...vector, [spec.axis]: Number(next) });
   const row = createFieldRow(
     { key: spec.key, label: spec.label, kind: 'number', default: 0, step: 1 },
     value,
-    {
-      onInput: (next) => {
-        const target = currentObject(host.state, sceneId, objectId);
-        if (!target) return;
-        if (!original) original = { ...spec.read(target) };
-        spec.write(target, withAxis(spec.read(target), next));
-        host.state.preview();
-      },
-      onChange: (next) => {
-        const target = currentObject(host.state, sceneId, objectId);
-        if (!target) return;
-        const previous = original ?? { ...spec.read(target) };
-        if (original) spec.write(target, { ...original });
-        original = undefined;
-        host.state.execute(spec.command(withAxis(previous, next)));
-      },
-    },
+    previewingHandlers<SceneObject, V>(host, {
+      target: () => currentObject(host.state, sceneId, objectId),
+      // Copied: the snapshot outlives the scrub, the vector in the model does not.
+      read: (object) => ({ ...spec.read(object) }),
+      write: spec.write,
+      toModel: (next, object) => withAxis(spec.read(object), next),
+      commit: spec.command,
+    }),
     spec.reset,
     spec.apply,
   );
@@ -224,34 +215,17 @@ function componentRow<V extends object>(host: InspectorHost, sceneId: string, ob
  * the container is placed, never at draw time.
  */
 function propertyRow(host: InspectorHost, sceneId: string, objectId: string, def: PropertyDef, values: Record<string, PropertyValue>): FieldRow {
-  let original: PropertyValue | undefined;
-  let hadOverride = false;
   const bases = () => deviations(host.state, sceneId, objectId, def.key);
   const row = createFieldRow(
     def,
     values[def.key] ?? def.default,
-    {
-      onInput: (value) => {
-        const target = currentObject(host.state, sceneId, objectId);
-        if (!target) return;
-        if (original === undefined) {
-          hadOverride = isOverridden(target, def.key);
-          original = target.overrides[def.key] ?? values[def.key] ?? def.default;
-        }
-        target.overrides[def.key] = value;
-        host.state.preview();
-      },
-      onChange: (value) => {
-        const target = currentObject(host.state, sceneId, objectId);
-        if (!target) return;
-        if (original !== undefined) {
-          if (hadOverride) target.overrides[def.key] = original;
-          else delete target.overrides[def.key];
-        }
-        original = undefined;
-        host.state.execute(new SetOverrideCommand(sceneId, objectId, def.key, value));
-      },
-    },
+    previewingHandlers<SceneObject>(host, {
+      target: () => currentObject(host.state, sceneId, objectId),
+      read: (object) => object.overrides[def.key],
+      write: (object, value) => (object.overrides[def.key] = value),
+      remove: (object) => delete object.overrides[def.key],
+      commit: (value) => new SetOverrideCommand(sceneId, objectId, def.key, value),
+    }),
     () => {
       const { template, asset } = bases();
       return [