Foundations PL4 1.20.1 — 0.2a-port.3 alpha candidate

Performance-only update. Index network membership and storage-node lists during topology rebuild. Reader target lookup and wireless-storage node lookup use the index instead of scanning every network group. Transfer rates, filters, ownership, and gameplay rules are unchanged.

Exact Forge compilation and 191 native GameTests gate publication of this revision. Installed client visuals, optional provider compatibility, multiplayer, large-network benchmarks and full PL2 parity remain pending. Alpha candidate.