Rounds ff607a1e0 + 7df0b94c9 delete the union-AABB scissor fallback, the
sky's doorway scissor bracket and the TerrainClip UBO; AD-17 now describes
the two surviving portal-polygon clips and their overflow behavior, and
AP-117 records that the walk's ported landcell_check feeds the production
particle in-view state. The three-lens re-review is owed post-hoc (API
overload); the lead's item-by-item verification is in the ledger.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>