Autotiles are a new asset type with a tab that shows every tile of the floor (2x3) or wall (2x2) block and an animated sample pattern (#118)

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

src/core/store/serialize.ts

@@ -168,6 +168,13 @@ 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') {
+      // 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(
+        (id): id is string => typeof id === 'string' && id !== '',
+      );
+      assets.push({ id, type, name, props, pictures });
     } else if (type === 'animation') {
       // A root or row aiming at something gone is kept: it reads as missing and keeps its keys.
       const root = typeof a.root === 'string' ? a.root : '';