fix(anim): Phase L.1c anchor monster MoveTo prediction

Keep the retail MoveTo speed/runRate parsing from 9812965 for animation playback, but do not use the partial MoveTo state as a body-position solver. Until the full retail MoveToManager target path is ported, retain UpdatePosition-derived velocity for server-controlled creature position and prevent that velocity from clobbering the packet-derived animation cycle speed.

src/AcDream.App/Rendering/GameWindow.cs

@@ -226,8 +226,9 @@ public sealed class GameWindow : IDisposable
         /// <summary>
         /// True while a server MoveToObject/MoveToPosition packet is the
         /// active locomotion source. Retail runs these through MoveToManager
-        /// and CMotionInterp using the packet's runRate; deriving velocity
+        /// and CMotionInterp using the packet's runRate; until we port the
-        /// from sparse UpdatePosition deltas under-speeds combat chases.
+        /// full target solver, use this only to protect packet-derived
+        /// animation speed from velocity-cycle clobbering.
         /// </summary>
         public bool ServerMoveToActive;
         /// <summary>
@@ -2452,16 +2453,6 @@ public sealed class GameWindow : IDisposable
                 if (_remoteDeadReckon.TryGetValue(update.Guid, out var remoteMot))
                 {
                     remoteMot.ServerMoveToActive = update.MotionState.IsServerControlledMoveTo;
-                    if (remoteMot.ServerMoveToActive && !IsPlayerGuid(update.Guid))
-                    {
-                        // Retail MoveTo packets already carry enough state
-                        // for CMotionInterp to drive velocity. A velocity
-                        // inferred from sparse UpdatePosition packets lags
-                        // during combat chases and visibly under-speeds the
-                        // run cycle until the next hard snap.
-                        remoteMot.HasServerVelocity = false;
-                        remoteMot.ServerVelocity = System.Numerics.Vector3.Zero;
-                    }
 
                     // Forward axis (Ready / WalkForward / RunForward / WalkBackward).
                     remoteMot.Motion.DoInterpretedMotion(
@@ -2685,6 +2676,11 @@ public sealed class GameWindow : IDisposable
         if (IsPlayerGuid(serverGuid)) return;
         if (rm.Airborne) return;
         if (ae.Sequencer is null) return;
+        // MoveTo packets already seeded the retail speed/runRate cycle.
+        // Keep UpdatePosition-derived velocity for render position only;
+        // using it to choose the cycle reverts fast chases back to slow
+        // velocity-estimated animation.
+        if (rm.ServerMoveToActive) return;
 
         var plan = AcDream.Core.Physics.ServerControlledLocomotion
             .PlanFromVelocity(velocity);
@@ -2771,7 +2767,6 @@ public sealed class GameWindow : IDisposable
             System.Numerics.Vector3? serverVelocity = update.Velocity;
             if (serverVelocity is null
                 && !IsPlayerGuid(update.Guid)
-                && !rmState.ServerMoveToActive
                 && rmState.LastServerPosTime > 0.0)
             {
                 double elapsed = nowSec - rmState.LastServerPosTime;
@@ -5047,6 +5042,15 @@ public sealed class GameWindow : IDisposable
                             rm.Body.Velocity = rm.ServerVelocity;
                         }
                     }
+                    else if (!IsPlayerGuid(serverGuid) && rm.ServerMoveToActive)
+                    {
+                        // We only parse enough of MoveTo to recover retail
+                        // animation speed. Do not let apply_current_movement
+                        // extrapolate position from an incomplete target
+                        // solver; hold until the next UpdatePosition-derived
+                        // velocity arrives.
+                        rm.Body.Velocity = System.Numerics.Vector3.Zero;
+                    }
                     else
                     {
                         rm.Motion.apply_current_movement(cancelMoveTo: false, allowJump: false);