Why: establish the authorized task workspace and its initial baseline.
Evidence: preserved precheck receipt in .task/feature-collab-storage-u4-migrator.md; R0=80a518628c526fd6ddece4abeb707ab4bb0b5618.
Impact: task metadata only; the feature workspace starts at 80a518628c.
Refs: .task/feature-collab-storage-u4-migrator.md