fix(attachments-storage-react-native): await File.move before reading size in moveFile

Author: icole

.changeset/fix-move-file-race.md

@@ -0,0 +1,5 @@
+---
+'@powersync/attachments-storage-react-native': patch
+---
+
+Fix `ExpoFileSystemStorageAdapter.moveFile` returning a stale size.

packages/attachments-storage-react-native/src/ExpoFileSystemStorageAdapter.ts

@@ -101,7 +101,7 @@ To use the Expo File System attachment adapter please install expo-file-system (
       if (target.exists) {
         target.delete();
       }
-      new this.File(sourceUri).move(target);
+      await new this.File(sourceUri).move(target);
     }
     return new this.File(targetUri).size ?? 0;
   }