Why: establish the authorized task workspace and its initial baseline.
Evidence: preserved precheck receipt in .task/fix-multiuser-collab-followups.md; R0=aa9f98d2e5b8ce36724f881752b0a95a353df987.
Impact: task metadata only; the feature workspace starts at aa9f98d2e5.
Refs: .task/fix-multiuser-collab-followups.md