docs(#184): CLOSE — Slice 2 gate passed (players walk through, monsters collide)

Slice 2 (2a e1ac56cc extract + 2b ddb5a967 fork-collapse) shipped and the visual
gate PASSED (user: "Looks good"), closing #184. Mark ISSUES #184 DONE and the Slice 2
handoff DONE, both noting the review-driven correction: non-PK players WALK THROUGH
each other (retail PvP), so the player win is monster/terrain/wall collision, not
player-vs-player de-overlap.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/research/2026-07-07-184-slice2-unify-extract-handoff.md

@@ -1,8 +1,12 @@
 # Handoff: #184 Slice 2 — extract `RemotePhysicsUpdater` (2a) + unify the player/NPC remote fork (2b)
 
-**Date:** 2026-07-07 · **Status:** PLANNED + DE-RISKED, implementation NOT started (deliberately
-deferred to a fresh focused session). **Decision (user):** do the FULL 2a + 2b (not the focused-2b
-subset) in a new session.
+**Date:** 2026-07-07 · **Status:** ✅ DONE — 2a shipped `e1ac56cc` (byte-exact extract), 2b shipped
+`ddb5a967` (fork collapse), **visual gate PASSED 2026-07-08 (user: "Looks good") → #184 FULLY CLOSED.**
+A 3-lens adversarial review (workflow `wf_b163315b-14f`) corrected the plan below in one place: the
+player gate is NOT "players de-overlap" — retail lets two non-PK players WALK THROUGH each other (PvP
+exemption), so the remote-player mover was given `IsPlayer|EdgeSlide` (§4-adjacent). 2b's player win is
+that players now collide with monsters + terrain + walls (Path A skipped all collision) while still
+passing through each other. See the physics digest banner + ISSUES #184 for the shipped writeup.
 
 **Read these first (in order):**
 1. This handoff — the plan, the exact sites, the #40 verdict, the seams.