docs(page-tree): correct isUnloadedBranch comment — no DnD-guard consumer (#525 review)

The comment falsely listed a 'DnD move guard' consumer; no DnD path routes
through the predicate (local DnD/create-page use the raw index-based insert).
List the real consumers (handleToggle + realtime insertByPosition/placeByPosition)
and note the local raw-insert path as a #525 follow-up. Comment-only.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/client/src/features/page/tree/components/space-tree.tsx

@@ -281,9 +281,11 @@ const SpaceTree = forwardRef<SpaceTreeApi, SpaceTreeProps>(function SpaceTree(
       setOpenTreeNodes((prev) => ({ ...prev, [id]: isOpen }));
       if (isOpen) {
         const node = treeModel.find(data, id) as SpaceTreeNode | null;
-        // Same "unloaded branch" predicate the insert paths use (`isUnloadedBranch`)
-        // so the lazy-load gate and the realtime/DnD inserts can never disagree
-        // about what counts as unloaded (#525).
+        // Same "unloaded branch" predicate the realtime insert paths use
+        // (`isUnloadedBranch`) so the lazy-load gate and the realtime inserts
+        // (`insertByPosition` / `placeByPosition`) can never disagree about what
+        // counts as unloaded (#525). Note: local raw `insert` (DnD/create-page)
+        // does not yet route through it — see #525 follow-up.
         if (treeModel.isUnloadedBranch(node)) {
           const fetched = await fetchAllAncestorChildren({
             pageId: id,

apps/client/src/features/page/tree/model/tree-model.ts

@@ -49,9 +49,11 @@ export const treeModel = {
   // resetting collapsed branches), NOT `children: undefined` — so a predicate that
   // only checks `=== undefined` misses the real case and materializes a misleading
   // partial list (#525). This is the SINGLE source of truth for "should a
-  // fetch/materialize be deferred?", shared by the lazy-load gate (`handleToggle`),
-  // the realtime insert path (`insertByPosition`) and the DnD move guard, so they
-  // can never drift apart again. A parent WITHOUT `hasChildren` is genuinely empty
+  // fetch/materialize be deferred?", shared by the lazy-load gate (`handleToggle`)
+  // and the realtime insert paths (`insertByPosition` / `placeByPosition`), so they
+  // can never drift apart again. (The local raw `insert` primitive and its DnD/
+  // create-page callers do NOT yet route through this predicate — see #525
+  // follow-up.) A parent WITHOUT `hasChildren` is genuinely empty
   // (no server children) — inserting its first child is correct, not deferred.
   isUnloadedBranch<T extends object>(
     node: TreeNode<T> | null | undefined,