- make addTreeNode receivers idempotent (invalidateOnCreatePage guard +
buildTree dedup) so the author's self-echo no longer duplicates the node
- broadcast realtime tree updates for bulk copy/duplicate and import via a
root refetch: PAGE_CREATED now carries spaceId and the WS listener falls
back to refetchRootTreeNodeEvent when no per-node snapshot is present
- remove the now-dead client-relay inbound path (isTreeEvent/handleTreeEvent)
that remained a stale-restriction-cache attack surface
- honest string|null cast for a root move's parent id
- add tests: buildTree dedup; onPageCreated per-node vs refetch branching
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
