fix(#171): R5-V3 — bind sticky melee (StickyManager live) + real arrival radii

Group-melee interpenetration + facing drift: the R5-V1-ported
StickyManager/PositionManager were Core-only — the StickTo/Unstick seams
were unbound and every arrival radius was 0, so ACE's Sticky|UseSpheres
melee chases closed ~one body-radius too deep and froze at stale arrival
poses until the next wire re-arm. Retires TS-39.

Wiring (anchors re-verified against the named decomp this session):
- EntityPhysicsHost owns a PositionManager; HandleUpdateTarget fans
  MoveToManager then PositionManager (CPhysicsObj::HandleUpdateTarget
  0x00512bc0 order).
- Seams bound remote + player: MoveToManager.StickTo (BeginNextNode
  sticky arrival @0x00529d3a), Unstick (PerformMovement head), and
  MotionInterpreter.UnstickFromObject (UM funnel head, 0x0050eaea).
- AdjustOffset at the retail UpdatePositionInternal slot (@0x00512d0e):
  NPC branch composes pre-sweep (steer is swept by ResolveWithTransition);
  remote-player branch chains the combiner offset through the shared
  delta frame (the interp stage) so sticky OVERWRITES when armed
  (0x00555430 assigns m_fOrigin, not accumulates); player inside the
  30 Hz physics quantum before UpdatePhysicsInternal.
- UseTime (the 1 s lease watchdog) at the UpdateObjectInternal tail
  (@0x005159b3): unconditional per remote; player gated on the physics
  tick (retail's MinQuantum gate skips UseTime too).
- Real setup cylsphere radii (CPartArray::GetRadius/GetHeight
  0x005180a0/0x005180b0 = setup radius/height x ObjScale from the spawn
  record): own via EnsureRemoteMotionBindings + player wiring; target via
  RouteServerMoveTo AND the speculative use-walk install (retail resolves
  the target PartArray at EVERY MoveToObject site — ACE PhysicsObj.cs:951).
- Teardown parity: exit_world (0x00514e60) UnStick + ClearTarget before
  the ExitWorld notify; player teleport fires teleport_hook's tail
  (UnStick in SetPosition + EntityPhysicsHost.NotifyTeleported =
  ClearTarget + NotifyVoyeurOfEvent(Teleported) @0x00514f1b) so mobs
  stuck to the player drop their sticks on a recall.
- SERVERVEL arbitration also yields to a stuck entity (same starvation
  class as the #170 fix — sticky owns the between-snap translation).
- StickyManager.UseTime aligned to retail's strict > deadline
  (0x00555626; ACE >): two V1 tests had pinned the >= edge — corrected.

Register: TS-39 deleted; TS-41 narrowed (stickyArmed gate); TS-43 added
(remote teleport_hook gap — self-corrects within the 1 s lease); AP-23
narrowed (real radii at the speculative site; only the use-radius
buckets remain invented).

Conformance: 2 new full-stack sticky scenarios in
RemoteChaseEndToEndHarnessTests (arrive -> stick -> strafing-target
gap+facing track -> lease expiry; unstick-on-rearm -> re-stick).
Full suite 4038 green.

Pre-commit adversarial diff review (3 lenses + per-finding refuters)
confirmed and fixed 4 findings: ObjScale-dead radius read, player
UseTime order inversion, missing teleport voyeur notify, speculative-
site radius asymmetry.

Awaiting the user visual gate: pack melee side-by-side vs retail
(attackers reshuffle + keep facing; some overlap is ACE-server-side).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.App/Rendering/EntityPhysicsHost.cs

@@ -24,9 +24,15 @@ namespace AcDream.App.Rendering;
 /// <see cref="HandleUpdateTarget"/> fan-out are injected by GameWindow so this
 /// class stays free of GameWindow's internals (code-structure rule #1).</para>
 ///
-/// <para>PositionManager (sticky) is R5-V3 — this host gains a
-/// <c>PositionManager</c> and <see cref="HandleUpdateTarget"/> fans to it then;
-/// V2 delivers only to the MoveToManager.</para>
+/// <para>R5-V3: owns a <see cref="PositionManager"/> too (retail
+/// <c>CPhysicsObj::position_manager</c> — retail creates it lazily via
+/// <c>get_position_manager</c>; acdream constructs it eagerly, which is
+/// behaviorally identical because the empty facade no-ops until its first
+/// <c>StickTo</c>/<c>ConstrainTo</c>). <see cref="HandleUpdateTarget"/> fans
+/// deliveries to the injected MoveToManager fan FIRST, then the
+/// PositionManager — retail <c>CPhysicsObj::HandleUpdateTarget</c> order
+/// (0x00512bc0: MovementManager @0x00512bf0, PositionManager
+/// @0x00512c1a).</para>
 /// </summary>
 public sealed class EntityPhysicsHost : IPhysicsObjHost
 {
@@ -68,6 +74,7 @@ public sealed class EntityPhysicsHost : IPhysicsObjHost
         _interruptCurrentMovement = interruptCurrentMovement
             ?? throw new ArgumentNullException(nameof(interruptCurrentMovement));
         _targetManager = new TargetManager(this);
+        PositionManager = new PositionManager(this);
     }
 
     // ── IPhysicsObjHost accessors ──────────────────────────────────────────
@@ -84,9 +91,24 @@ public sealed class EntityPhysicsHost : IPhysicsObjHost
     /// <c>CPhysicsObj::target_manager</c>).</summary>
     public TargetManager TargetManager => _targetManager;
 
+    /// <summary>R5-V3 — the owned <see cref="PositionManager"/> facade (retail
+    /// <c>CPhysicsObj::position_manager</c>): sticky follow + (unarmed)
+    /// constraint leash. Seam targets: <c>MoveToManager.StickTo/Unstick</c>,
+    /// <c>MotionInterpreter.UnstickFromObject</c>, the per-tick
+    /// <c>AdjustOffset</c>/<c>UseTime</c> drivers.</summary>
+    public PositionManager PositionManager { get; }
+
     // ── IPhysicsObjHost fan-out / target-tracking seams ────────────────────
     public IPhysicsObjHost? GetObjectA(uint id) => _getObjectA(id);
-    public void HandleUpdateTarget(TargetInfo info) => _handleUpdateTarget(info);
+
+    public void HandleUpdateTarget(TargetInfo info)
+    {
+        // Retail CPhysicsObj::HandleUpdateTarget (0x00512bc0) fan order:
+        // MovementManager (the injected MoveToManager fan) first, then
+        // PositionManager (@0x00512c1a — the R5-V3 sticky consumer).
+        _handleUpdateTarget(info);
+        PositionManager.HandleUpdateTarget(info);
+    }
     public void InterruptCurrentMovement() => _interruptCurrentMovement();
 
     public void SetTarget(uint contextId, uint objectId, float radius, double quantum)
@@ -112,4 +134,16 @@ public sealed class EntityPhysicsHost : IPhysicsObjHost
     /// stick/moveto). Called on despawn before the host is removed from the
     /// registry.</summary>
     public void NotifyExitWorld() => _targetManager.NotifyVoyeurOfEvent(TargetStatus.ExitWorld);
+
+    /// <summary>R5-V3 (#171): retail <c>CPhysicsObj::teleport_hook</c>'s tail
+    /// (0x00514ed0 @0x00514f1b-0x00514f28) — <c>TargetManager::ClearTarget</c>
+    /// (drop this entity's OWN subscription) then
+    /// <c>NotifyVoyeurOfEvent(Teleported)</c> (every entity watching THIS one
+    /// drops its stick/moveto — <c>StickyManager::HandleUpdateTarget</c>'s
+    /// non-Ok teardown path). Called after a teleport placement.</summary>
+    public void NotifyTeleported()
+    {
+        _targetManager.ClearTarget();
+        _targetManager.NotifyVoyeurOfEvent(TargetStatus.Teleported);
+    }
 }