Keep local physics authoritative at the retail 30 Hz MinQuantum, but expose a render-only position that lerps between completed physics ticks for the player mesh and chase-camera target. Network outbound continues to use the discrete physics position.
Also make the visually confirmed #47 humanoid close-detail DIDDegrade path default-on, with ACDREAM_RETAIL_CLOSE_DEGRADES=0 left as a diagnostic opt-out.
Verification: dotnet build AcDream.slnx -c Debug; focused #38 interpolation tests passed; visual confirmed smooth 2026-05-06. Full dotnet test AcDream.slnx -c Debug --no-build still has the known 8 AcDream.Core.Tests baseline failures.
Co-authored-by: Codex <codex@openai.com>
