Bite-sized plan for R1 (the per-cell DrawInside core): InteriorEntityPartition
(3-bucket, TDD), InteriorRenderer per-cell loop, the binary render decision in
OnRender (indoor = DrawInside only), and the :1756 bypass repurpose. Particles
deferred to R1b. Grounded in the live code surface (exact file:line + signatures).
Ends at the R1 user visual gate (sealed Holtburg cottage, no bleed).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
