Add File Browser fixed module reference

[cookesan]

Adds File Browser fixed module reference to GHSA-239w-m3h6-ch8v.

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-239w-m3h6-ch8v/GHSA-239w-m3h6-ch8v.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]

Revalidated July 8, 2026: this remains scoped to the fixed File Browser v2.63.14 Go module reference for GHSA-239w-m3h6-ch8v. The Go module page, upstream tag, and existing fix commit resolve; affected ranges, severity, and advisory metadata fields remain unchanged. Local checks passed with a single advisory JSON file changed, JSON parsing, git diff --check HEAD^..HEAD, and a clean worktree.