Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/schema-org/src/core/graph.ts`:
- Around line 125-131: The null-sentinel stripping (stripNullProperties) and
removal of node._resolver are happening per-node immediately after calling
node._resolver.resolveRootNode, which makes pass-2 resolvers see earlier nodes
with sentinels already erased; instead, defer calling stripNullProperties(node)
and delete node._resolver until after the entire second-pass resolution loop
completes (i.e., run resolveRootNode for every node first using
node._resolver.resolveRootNode(node, ctx) / ctx.find(), then in a subsequent
loop call stripNullProperties(node) and delete node._resolver for each node), so
all resolveRootNode handlers can observe null opt-out sentinels consistently.

In `@packages/schema-org/src/utils/index.ts`:
- Around line 164-177: The stripNullProperties function currently uses delete on
numeric keys which creates sparse arrays (holes) that JSON.stringify turns into
nulls; update stripNullProperties to detect arrays (Array.isArray(v)) and for
arrays remove null entries by constructing a new filtered array (e.g., v =
v.filter(el => el !== null)) or splice out nulls, then recurse into each
remaining element (calling stripNullProperties on object elements) instead of
deleting numeric indices; keep the existing __v_isReadonly and __v_isRef checks
and apply them to array elements as well, and assign the filtered array back to
obj[k] so callers of stripNullProperties (the function name) see a compact array
rather than a sparse one.

---

Nitpick comments:
In `@packages/schema-org/src/utils/index.ts`:
- Around line 54-56: The setIfEmpty function currently avoids setting defaults
when the provided value is falsy (0, false, ''), because the RHS uses
truthiness; update the conditional in setIfEmpty so it only treats undefined as
"no value" (i.e., check value !== undefined) while still requiring the
destination to be undefined (node?.[field] === undefined). Modify the logic in
the setIfEmpty function to use the explicit undefined check for the incoming
value so explicit falsy defaults are assigned.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/schema-org/src/core/graph.ts`:
- Around line 131-133: The loop currently calls
stripNullProperties(ctx.nodes[i]) before deleting ctx.nodes[i]._resolver, which
lets stripNullProperties traverse and mutate node._resolver; to fix, remove the
_resolver property before stripping by moving the delete into a prior pass or by
changing stripNullProperties to ignore the "_resolver" key—update the code
touching ctx.nodes (reference: ctx.nodes array, stripNullProperties function,
and the "_resolver" property) so that deletion of _resolver occurs before any
stripping operation (or add logic in stripNullProperties to skip "_resolver").