Case 3 of the characterization suite (a sync use_state write from a backend-fired handler
re-renders) is true of the ENGINE and was taken as license to de-hoist event-driven page
state — and the live app immediately disproved it: with settings componentized and its
scope local, a real ComboBox pick changed nothing on screen (UIA-verified, no repaint).
The real WinUI backend's handler wiring still never pumps the pass the harness pumps.
The de-hoist is reverted one commit back; this one makes the record honest. The module
discipline note now separates the three tiers of evidence — engine rules (harness-pinned),
real-backend behaviour (live-verified, hoisting stays), and the tween-keyed corollary —
and case 3's comment warns it must not be read as de-hoist permission without a live UIA
check. The upstream gap worth reporting grows to two: the AsyncSetState HostId registry
miss, and the backend event wiring that bypasses the render pump.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>