Add pnpm stage download advisory references

[cookesan]

Adds pnpm stage download advisory references to GHSA-v23m-ccfg-pq9h.

Audit refresh, July 8, 2026:

• Confirmed the live PR is open, ready for review, merge-clean, and the visible advisory check is green.
• Rechecked the merge-base diff: exactly one advisory JSON file changes (advisories/github-reviewed/2026/06/GHSA-v23m-ccfg-pq9h/GHSA-v23m-ccfg-pq9h.json), JSON parses, git diff --check passes, and the exact-head worktree is clean.
• Revalidated the added public references in the diff; all resolve through their source site or registry.

[cookesan]

Rechecked this reference-only PR while keeping the open Advisory Database queue current.

Adds direct commit and release references for GHSA-v23m-ccfg-pq9h. The advisory already references NVD, upstream PR #12303, and package source; this PR links the merged fix to the fixed pnpm release.

Current audit, July 8, 2026:

• GHSA-v23m-ccfg-pq9h is live and not withdrawn.
• CVE-2026-55700 resolves in NVD with Analyzed status.
• PR #12303 merged to main as commit 65443f4bdf1f0db9c8c7dc58fee25252607e9234.
• Release v11.5.3 is published and not marked draft or prerelease.
• npm pnpm 11.5.3 resolves with package tarball and integrity metadata.
• Local JSON validation and whitespace checks pass, and the diff only changes this advisory.

No advisory data fields are changed.