The crowd-tightness residual from the #182 gate: monsters overlap (arms) in acdream but
barely in retail on the SAME ACE. Verified root (workflow wf_d2ff782f-9cb + source): retail
runs UpdateObjectInternal+transition on EVERY remote creature (CPhysics::UseTime 0x00509950,
no fork) so they de-overlap client-side, with the server pos a gentle MoveOrTeleport catch-up
target (0x00516330), NOT a hard-snap. acdream (a) hard-snaps NPC remotes to the raw overlapping
server pos (GameWindow.cs:5925) overwriting the swept de-penetration, and (b) forks player-remotes
(skip sweep) from NPCs (sweep at :10558 but driven by get_state_velocity, not the catch-up).
Collision math already exists + is faithful; the fix is the reconciliation (hard-snap→catch-up)
+ the movement model (synth-velocity→interp catch-up) — a delicate rework of the frozen R4/R5
remote-DR arc, staged NPC-first. Design spec + full handoff (verified code sites, retail anchors,
preserve-list, gotchas, slices) written for a fresh session. Implementation NOT started.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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