A behavior has rows of its own, so loading no longer drops Run in editor

`deserializeProject` builds each asset's effective schema in pass 1 and coerces
`props` against it in pass 2. For a behavior that schema was
`[...COMMON_PROPS, ...variables]` -- but `runInEditor` lives in
`ASSET_SCHEMAS.behavior`, not in `COMMON_PROPS`, so `normalizeBag` dropped the
value as undeclared. The flag therefore survived no save: every reload switched
it back off.

The fix is the full schema, `schemaFor('behavior')`, which is what
`schemaForAsset` hands out everywhere else.

Found by a round-trip test comparing the whole project rather than one field. An
existing test had the loss written down as its expectation
(`{ enabled, speed }`), which is why nothing ever reported it.

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

src/core/store/serialize.ts

@@ -40,7 +40,6 @@ import {
 import { type FlatItem, makeFlatItem } from '../properties/listItems';
 import {
   coerceValue,
-  COMMON_PROPS,
   isValidFieldName,
   isValidVariableName,
   type PropertyDef,
@@ -76,7 +75,9 @@ export function deserializeProject(raw: unknown, fallbackId = ''): Project {
     if (a.type === 'behavior') {
       const vars = normalizeVariables(a.variables);
       variables.set(a.id, vars);
-      schemas.set(a.id, [...COMMON_PROPS, ...vars]);
+      // The full schema, not just the common rows: this is what pass 2 coerces `props` against, and
+      // a behavior's own `runInEditor` would be dropped as undeclared.
+      schemas.set(a.id, [...schemaFor('behavior'), ...vars]);
     } else if (a.type === 'particles') {
       // A source's rows end with its own graph's parameters, so the graph is needed before the
       // overrides of the objects placed from it can be coerced.

tests/core/graph.test.ts

@@ -475,7 +475,7 @@ describe('behavior serialization', () => {
     const loaded = findAsset(roundTrip(project), behavior.id) as BehaviorAsset;
     expect(loaded.variables).toEqual(behavior.variables);
     expect(loaded.graph).toEqual(behavior.graph);
-    expect(loaded.props).toEqual({ enabled: true, speed: 0 });
+    expect(loaded.props).toEqual({ enabled: true, runInEditor: false, speed: 0 });
 
     const raw = serializeProject(project) as {
       assets: { id: string; graph?: { nodes: unknown[]; edges: unknown[] } }[];

tests/core/serialize.test.ts

@@ -1,7 +1,8 @@
 import { describe, expect, it } from 'vitest';
+import { SetAssetPropertyCommand } from '../../src/core/commands/assetCommands';
 import { SetOverrideCommand } from '../../src/core/commands/sceneObjectCommands';
 import { deserializeProject } from '../../src/core/store/serialize';
-import { makeSpriteScene, place, roundTrip } from '../helpers';
+import { makeBehavior, makeSpriteScene, place, roundTrip } from '../helpers';
 
 describe('serialize', () => {
   it('round-trips a project', () => {
@@ -11,6 +12,15 @@ describe('serialize', () => {
     expect(roundTrip(f.project)).toEqual(f.project);
   });
 
+  /** A behavior's own rows are not the common ones: coercing against those alone dropped the value. */
+  it('keeps a behavior running in the editor across a save', () => {
+    const f = makeSpriteScene();
+    const behavior = makeBehavior(f, 'B');
+    f.stack.execute(new SetAssetPropertyCommand(behavior.id, 'runInEditor', true));
+    const loaded = roundTrip(f.project).assets.find((a) => a.id === behavior.id)!;
+    expect(loaded.props.runInEditor).toBe(true);
+  });
+
   it('repairs broken documents', () => {
     const project = deserializeProject(
       {