The autotile asset is renamed to tile and gains a plain None (1 × 1) kind, which is now the default; older projects load their autotiles as floor tiles (#131)

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

src/core/store/serialize.ts

@@ -79,7 +79,7 @@ import { SHADER_KEY, shaderParamDefs } from '../properties/shaders';
  */
 export function deserializeProject(raw: unknown, fallbackId = ''): Project {
   const r = asRecord(raw);
-  const rawAssets = (Array.isArray(r.assets) ? r.assets : []).map(asRecord);
+  const rawAssets = (Array.isArray(r.assets) ? r.assets : []).map(asRecord).map(migrateAsset);
 
   // Pass 1: asset ids and their effective schemas, needed to coerce overrides in pass 2.
   const schemas = new Map<string, PropertySchema>();
@@ -176,7 +176,7 @@ export function deserializeProject(raw: unknown, fallbackId = ''): Project {
     } else if (type === 'sound') {
       const file = typeof a.file === 'string' && isSoundFile(a.file) ? a.file : '';
       assets.push({ id, type, name, props, file });
-    } else if (type === 'autotile') {
+    } else if (type === 'tile') {
       // A picture naming nothing is kept, like an animation's dangling root: it reads as missing
       // in the tab and comes back when the texture it named is restored by an undo.
       const pictures = (Array.isArray(a.pictures) ? a.pictures : []).filter(
@@ -505,7 +505,7 @@ function normalizeTracks(raw: unknown): AnimationTrack[] {
 
 /**
  * The layers of a tilemap. A cell whose key is not a pair of whole numbers, or which names nothing,
- * is dropped; one naming a deleted autotile is kept, like an animation's dangling row, so an undo
+ * is dropped; one naming a deleted tile is kept, like an animation's dangling row, so an undo
  * brings the drawing back. A doubled layer id is dropped as a doubled node is.
  */
 function normalizeLayers(raw: unknown): TilemapLayer[] {
@@ -537,6 +537,17 @@ function normalizeBag(raw: unknown, schema: PropertySchema, sparse: boolean): Pr
   return bag;
 }
 
+/**
+ * A tile was called an autotile before it could be a plain one (#131). Such an asset had no kind
+ * but the autotile blocks, and one written without a kind meant a floor – which it has to stay now
+ * that a missing kind means a plain tile.
+ */
+function migrateAsset(a: Record<string, unknown>): Record<string, unknown> {
+  if (a.type !== 'autotile') return a;
+  const props = asRecord(a.props);
+  return { ...a, type: 'tile', props: { ...props, kind: props.kind ?? 'floor' } };
+}
+
 function asRecord(value: unknown): Record<string, unknown> {
   return value && typeof value === 'object' ? (value as Record<string, unknown>) : {};
 }