chore(143-04): deploy registry to Fly.io, trigger docs deploy, tag v14.0.0

- fly deploy --app mesh-registry succeeded (2 machines, iad region)
- GET https://api.packages.meshlang.dev/api/v1/packages returns 200 []
- GitHub Pages deploy.yml triggered and completed (v14 docs live)
- git tag v14.0.0 pushed to origin
- release.yml completed: 6 meshc + 4 meshpkg artifacts in GitHub Release v14.0.0

Author: snowdamiz