Remove outdated claims (CRDT, DocRooms, presence, .md files on disk) and
document the actual architecture, API, permissions and known flaws.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Task list shares now carry a permission (editor/viewer). The server rejects
writes from viewers with 403, and the UI hides or disables edit controls
for read-only lists.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>