fix(a11y-core): give ad-hoc virtual nodes a null parent

[Aaryan430]

What

Virtual nodes constructed outside the tree walk were created without a parent argument, leaving parent as undefined. axe uses undefined as the marker for a disconnected tree, so any closest() walk that reaches such a node throws:

TypeError: Cannot resolve parent for non-DOM nodes

These now pass null, which is the documented marker for the top of a tree (see the comment in get-flattened-tree.js), so the walk terminates normally instead of throwing.

getOwnedVirtual additionally filters the resolved nodes. getNodeFromTree returns undefined for an aria-owns reference that is not in the current tree; the existing filter only removed empty refs before resolution, so undefined entries were passed through to callers.

Changes

File	Change
lib/commons/dom/create-grid.js	new VirtualNode(document.documentElement, null)
lib/core/utils/dq-element.js	new VirtualNode(element, null)
lib/commons/aria/get-owned-virtual.js	filter resolved nodes, not just refs

10 insertions, 3 deletions. All three carry // [a11y-critical]: tags.

Testing

Suite	Result
eslint on the three files	clean
karma testDirs=core	1510 passed, 40 failed
karma testDirs=commons	2107 passed, 12 failed

The failing tests are pre-existing in this environment. Both suites were run against a rebuilt baseline with the change stashed, and the failure sets are byte-identical before and after — no test changes state. No test in create-grid, get-owned-virtual, closest or dq-element fails.

🤖 Generated with Claude Code

[securityscaapp]

⚠️ Git Merge Conflict Detected

Error Details:

Error occured while merging master/main - Cmd('git') failed due to: exit code(1)
  cmdline: git merge main
  stdout: 'Auto-merging lib/commons/aria/get-owned-virtual.js
CONFLICT (content): Merge conflict in lib/commons/aria/get-owned-virtual.js
Automatic merge failed; fix conflicts and then commit the result.'

How to Fix:

1. Pull the latest changes from the target branch
2. Resolve the merge conflicts in the affected files
3. After resolving conflicts, stage the changes: git add <resolved-files>
4. Complete the merge: git commit
5. Push your changes and re-run the SCA scan

💡 Tip: Use git status to see which files have conflicts.