Why: establish the authorized task workspace and its initial baseline.
Evidence: preserved precheck receipt in .task/feature-generative-ui-u6-gate-record.md; R0=fefb3e060ec05cdadc6ee8bc55abff730fe79e21.
Impact: task metadata only; the feature workspace starts at fefb3e060e.
Refs: .task/feature-generative-ui-u6-gate-record.md