A resource was private with no way out but the author's own Nextcloud.
Share opens reading — open, preview, download — to one person at a time by
exact email (no account is ever listed) or to everyone signed in with one
switch; what others share appears in your library marked "Shared by …".
Writing never travels: modify, re-skin, delete and the share list stay the
author's, every write still filtered on user_id, and the read routes go
through one reader rule. Rows follow the resource and the person.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Dv6sqaY6Vq3ChZHMem3cnU