The broken-state log (user-session-capture2.log) shows meshMissing=0 /
entSeen==entDrawn WHILE broken stairs are on screen - the staircase is
DRAWN WRONG, not missing. This probe discriminates the three live
hypotheses in ONE launch (handoff 2026-06-11 s4):
- HYDRATE dump (GameWindow.BuildInteriorEntitiesForStreaming): per-part
placement-frame translations + dropped-part accounting at the MOMENT
MeshRefs are constructed. H-A (SetupMesh.Flatten identity fallback /
silent gfx-null part drops under degraded dat reads) shows here as
zero translations or built<43.
- DRAW dump (WbDrawDispatcher, first tuple per entity): live MeshRefs
translation summary + per-part loaded flags + Tier-1 classification
cache state (batch count + RestPose translation summary), re-emitted
compactly on signature change. H-B (partial/stale cached batch set)
shows as correct translations + odd batch count.
- WALK-REJECT lines (rate-limited): attributes 'entity never reaches
the draw loop' to the specific gate (visibleCellIds/frustum).
- Correct everything -> H-C (draw-side compose), instrument next.
Targets: ACDREAM_DUMP_ENTITY=0x020003F2,0x020005D8 (the 43-part spiral
staircase Setup + the wall barrels; H-A predicts the user's 'barrel' IS
the collapsed staircase). Probe is inert when the env var is unset.
Parser in RenderingDiagnostics (diagnostic-owner pattern) + 5 unit tests.
Suites: App 242+1skip / Core 1427+2skip / UI 420 / Net 294.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>