Add Gitea fork authorization fix references

[cookesan]

Adds Gitea fork authorization fix references to GHSA-fhx7-m96w-mv29.

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-fhx7-m96w-mv29/GHSA-fhx7-m96w-mv29.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]

Maintainer audit: this only expands the reference set for the Gitea fork authorization advisory. go-gitea/gitea#36950 is merged, commit 686d10b7f0c26baf91171124b382cbcdfa7bf025 resolves, and the v1.26.0 release blog, release tag, and Go module record resolve. The advisory JSON parses, the committed diff passes git diff --check, the PR is merge-clean, and advisory processing is successful. No package, affected range, severity, or database metadata is changed.