Harden Zulu metadata pagination with safety cap

- Stop paginating on a short page to avoid an extra empty request
- Guard against undefined results (not just null)
- Cap iterations at 100 pages and warn if the limit is hit to
  prevent a runaway loop if the API misbehaves

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: brunoborges