- new is_admin column on invites (migration 4) with DEFAULT 0
- requireAdmin middleware returns 404 for non-admins so the route's
existence isn't leaked; path obscured as /fenjaops (not /admin)
- admin/ dir lives outside public/ and protected/; only reachable via
the explicit gated mount + /api/fenjaops/{invites,joins} endpoints
- bin/invite.js gains `admin add|remove|list` subcommands
- OPERATIONS.md + CLAUDE.md + PROJECT.md document the hidden URL
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>