fix: version reporting on lith — write and find .commit-ref
The version function only checked cwd/public/.commit-ref (Netlify path).
On lith, cwd is /opt/ac/lith so the file was never found, causing stale
"50 behind" display. Now checks ../system/public/.commit-ref too.
Also: deploy.fish writes .commit-ref after pull, excludes .netlify from
rsync to prevent stalls on edge function cache files.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>