Password-gated deck

This feature is in the catalog but no capture exists for it. That's an honest gap, not a broken page.

Note from the last run: Not walked: no deck in the registry is currently marked protected, so the gate has nothing to guard and cannot be reached honestly. The admin dashboard confirms it — Password Protected reads 0.

/walkthrough /auth/[slug] --project=openstage

Run that in Claude Code or Codex from the repo root.