index 48ed856..70519ef 100644
@@ -20,6 +20,7 @@ Style: Karpathy-ish. Pages are short, focused, opinionated, cross-referenced. Wh
### Inheritance & positioning
- [cortex-inheritance.md](cortex-inheritance.md) — R1-R19 adopt/adapt/reject/defer map
+- [piyush-era-design.md](piyush-era-design.md) — study of pre-container Cortex; source of Option 2
- [relationship-to-noos.md](relationship-to-noos.md) — what picortex shares with noos, and what it doesn't
- [openchat-adapter.md](openchat-adapter.md) — future third channel
- [repo-versions.md](repo-versions.md) — GitHub latest-sha pins for every referenced repo