Design for opt-in --multiuser: per-user case spaces, scrypt-hashed
users.json, ownership threading across sessions/cases/SSE/push, admin
panel, and a per-user Claude permission-mode policy. Reviewed against
the actual auth/SSE/case/session code; the plan encodes verified
call-site inventories, the non-admin workingDir confinement rule,
WS-upgrade identity plumbing, per-user QR minting, and the linked-cases
v2 format migration.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>