/whats-next batch activation for the D-243 region-tier finish.
Refinement briefs (Si pass) appended to T-1042 and T-1078 reconciling
their 2026-06-12 scope against the post-T-1077 tree. T-1046 (Region→
Chunk→Voxel wiring) flipped to done — already committed in cfd5e18d0.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>