Add dual-run flags/meter, harden task-status (idempotency, UUID, head,
push), State Hub adapter for PATCH /tasks and C-15/reconcile proxy, pilot
evidence, and finish RMGR-WP-0002.
Document how State Hub registers, resolves, reconciles, and mutates
repos; blueprint Stage B dual-run toward retirement; open workplan for
SH adapter writeback/reconcile without non-retirement refactors.