fix(R4-V5): moveto stall #2 - login SetPosition ran before the sink bind, orphaning one immortal pending_motions node

The c2dc1a88 wedge fix paired every StopCompletely A9 node with a
completable motion-table type-5 entry via DefaultSink?.StopCompletely()
- but EnterPlayerModeNow called the initial SetPosition (whose teleport
idle is StopCompletely, R3-W6) BEFORE the sequencer/DefaultSink bind
block, so the login A9 node dispatched against a NULL sink and stayed
an orphan. Head-pop-any semantics mean a queue with one orphan never
reaches empty again (later completions just relabel the backlog), so
MotionsPending stayed true at every UseTime and the MoveToManager's
retail wait-for-anims gate (BeginTurnToHeading) never opened: every
server MoveTo armed (movingTo=True, Initialized=True, tracker fed,
node plan built) and the body never moved.

Pinned live by the [autowalk-gate] probe: type=MoveToObject init=True
contact=True motionsPending=True pm=[0x41000003] nodes=[TurnToHeading,
MoveToPosition] curCmd=0 - identical every half-second, forever.

Fix: the sequencer/sink bind block in EnterPlayerModeNow moves ABOVE
the initial physics Resolve + SetPosition (no data dependency - the
block only needs playerEntity/_animatedEntities). Teleport-arrival
SetPositions were already safe (sink long bound). Test rigs
(PlayerMoveToCutoverTests.MakeRig, W6EdgeDrivenMovementTests) mirror
the fixed order, and a new LoginQueue_DrainsToEmpty_UnderProductionFeed
test pins the invariant the probe caught: after login, pending_motions
must reach EMPTY under the production completion feed.

The [autowalk-gate]/[autowalk-feed] diagnostics stay in for the live
verify pass (TEMPORARY-tagged; strip when #5 closes). Full suite
green: 3,958.

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

src/AcDream.App/Input/PlayerMovementController.cs

@@ -198,6 +198,8 @@ public sealed class PlayerMovementController
     private bool _prevTurnLeftHeld;
     private bool _prevTurnRightHeld;
     private bool _prevRunHeld;
+    // TEMPORARY diagnostic clock (2026-07-03 moveto-stall investigation).
+    private float _lastAutowalkGateLogTime = float.MinValue;
 
     // Heartbeat timer.
     // Cadence is 1.0 sec to match holtburger's
@@ -526,6 +528,22 @@ public sealed class PlayerMovementController
         // slot drains.
         _motion.CheckForCompletedMotions?.Invoke();
 
+        // TEMPORARY diagnostic (2026-07-03 moveto-stall investigation,
+        // strip when closed): every gate input the armed moveto's per-tick
+        // drive depends on, ~2 Hz while armed, ProbeAutoWalk-gated.
+        if (PhysicsDiagnostics.ProbeAutoWalkEnabled
+            && MoveTo is { } mtDiag && mtDiag.IsMovingTo()
+            && _simTimeSeconds - _lastAutowalkGateLogTime > 0.5f)
+        {
+            _lastAutowalkGateLogTime = _simTimeSeconds;
+            var pmParts = new System.Collections.Generic.List<string>();
+            foreach (var n in _motion.PendingMotions) pmParts.Add($"0x{n.Motion:X8}");
+            var nodeParts = new System.Collections.Generic.List<string>();
+            foreach (var n in mtDiag.PendingActions) nodeParts.Add(n.Type.ToString());
+            Console.WriteLine(System.FormattableString.Invariant(
+                $"[autowalk-gate] type={mtDiag.MovementTypeState} init={mtDiag.Initialized} tlid=0x{mtDiag.TopLevelObjectId:X8} contact={_body.InContact} motionsPending={_motion.MotionsPending()} pm=[{string.Join(",", pmParts)}] nodes=[{string.Join(",", nodeParts)}] curCmd=0x{mtDiag.CurrentCommand:X8} auxCmd=0x{mtDiag.AuxCommand:X8} fwd=0x{_motion.InterpretedState.ForwardCommand:X8} pos=({Position.X:F1},{Position.Y:F1}) yaw={Yaw:F2}"));
+        }
+
         // Portal-space guard: while teleporting, no input is processed and
         // no physics is resolved. Return a zero-movement result so the caller
         // can detect the frozen state (MotionStateChanged = false, no commands).

src/AcDream.App/Rendering/GameWindow.cs

@@ -7927,6 +7927,11 @@ public sealed class GameWindow : IDisposable
                             _playerMoveToTargetGuid,
                             AcDream.Core.Physics.Motion.TargetStatus.Ok,
                             tp, tp));
+                        if (AcDream.Core.Physics.PhysicsDiagnostics.ProbeAutoWalkEnabled)
+                        {
+                            Console.WriteLine(System.FormattableString.Invariant(
+                                $"[autowalk-feed] Ok guid=0x{_playerMoveToTargetGuid:X8} pos=({tpos.X:F1},{tpos.Y:F1}) init={playerMtm.Initialized}"));
+                        }
                     }
                 }
                 else
@@ -13058,6 +13063,35 @@ public sealed class GameWindow : IDisposable
             int plbY = _liveCenterY + (int)MathF.Floor(playerEntity.Position.Y / 192f);
             pinitCellId = ((uint)plbX << 24) | ((uint)plbY << 16) | 0x0001u;
         }
+        // R4-V5 moveto-stall fix #2 (2026-07-03, the [autowalk-gate] probe's
+        // one-immortal-node finding): the sequencer/sink bind block MUST run
+        // BEFORE the initial SetPosition. SetPosition → StopCompletely
+        // enqueues the A9 pending_motions node whose completable partner is
+        // the DefaultSink's type-5 motion-table entry — with the sink still
+        // null at login, the node was ORPHANED, and pending_motions never
+        // reached empty again (head-pop-any just relabels a backlog), so
+        // the MoveToManager's wait-for-anims gate never opened: every
+        // server MoveTo armed but the body never moved.
+        if (_animatedEntities.TryGetValue(playerEntity.Id, out var playerAE)
+            && playerAE.Sequencer is { } playerSeq)
+        {
+            _playerController.AttachCycleVelocityAccessor(() => playerSeq.CurrentVelocity);
+            // R3-W4: bind the player interp's retail seams to the player
+            // sequencer — LeaveGround/HitGround strip transition links here
+            // (the K-fix18 replacement).
+            _playerController.Motion.RemoveLinkAnimations = playerSeq.RemoveAllLinkAnimations;
+            _playerController.Motion.InitializeMotionTables =
+                () => playerSeq.Manager.InitializeState();
+            _playerController.Motion.CheckForCompletedMotions =
+                playerSeq.Manager.CheckForCompletedMotions;
+            // R3-W6: the player's cycles are now driven through the SAME
+            // dispatch sink remotes use (TurnApplied/TurnStopped omitted —
+            // ObservedOmega is a remote-DR-only concept; local rotation is
+            // the controller's Yaw integration).
+            _playerController.Motion.DefaultSink =
+                new AcDream.Core.Physics.Motion.MotionTableDispatchSink(playerSeq);
+        }
+
         var initResult = _physicsEngine.Resolve(
             playerEntity.Position, pinitCellId,
             System.Numerics.Vector3.Zero, 100f);
@@ -13072,27 +13106,6 @@ public sealed class GameWindow : IDisposable
         playerEntity.SetPosition(initResult.Position);
         playerEntity.ParentCellId = initResult.CellId;
 
-        if (_animatedEntities.TryGetValue(playerEntity.Id, out var playerAE)
-            && playerAE.Sequencer is { } playerSeq)
-        {
-            _playerController.AttachCycleVelocityAccessor(() => playerSeq.CurrentVelocity);
-            // R3-W4: bind the player interp's retail seams to the player
-            // sequencer — LeaveGround/HitGround strip transition links here
-            // (the K-fix18 replacement); DefaultSink stays null until R3-W6
-            // (UpdatePlayerAnimation still drives the player's cycles).
-            _playerController.Motion.RemoveLinkAnimations = playerSeq.RemoveAllLinkAnimations;
-            _playerController.Motion.InitializeMotionTables =
-                () => playerSeq.Manager.InitializeState();
-            _playerController.Motion.CheckForCompletedMotions =
-                playerSeq.Manager.CheckForCompletedMotions;
-            // R3-W6: the player's cycles are now driven through the SAME
-            // dispatch sink remotes use (TurnApplied/TurnStopped omitted —
-            // ObservedOmega is a remote-DR-only concept; local rotation is
-            // the controller's Yaw integration).
-            _playerController.Motion.DefaultSink =
-                new AcDream.Core.Physics.Motion.MotionTableDispatchSink(playerSeq);
-        }
-
         var q = playerEntity.Rotation;
         float rawYaw = MathF.Atan2(
             2f * (q.W * q.Z + q.X * q.Y),

tests/AcDream.Core.Tests/Input/PlayerMoveToCutoverTests.cs

@@ -114,14 +114,19 @@ public class PlayerMoveToCutoverTests
     private static Rig MakeRig(out AnimationSequencer seqOut)
     {
         var controller = new PlayerMovementController(MakeFlatEngine());
-        controller.SetPosition(new Vector3(96f, 96f, 50f), 0x0001);
-        controller.Yaw = 0f; // heading 90 = facing +X
         var seq = MakeSequencer();
         seqOut = seq;
+        // Production (EnterPlayerModeNow) order: the sink binds BEFORE the
+        // initial SetPosition — SetPosition → StopCompletely needs the sink
+        // for its type-5 motion-table dispatch, the completable partner of
+        // the A9 pending_motions node (a null sink orphans it and the
+        // MoveToManager wait-for-anims gate never opens — the live stall).
         controller.Motion.DefaultSink = new MotionTableDispatchSink(seq);
         controller.Motion.RemoveLinkAnimations = seq.RemoveAllLinkAnimations;
         controller.Motion.InitializeMotionTables = () => seq.Manager.InitializeState();
         controller.Motion.CheckForCompletedMotions = seq.Manager.CheckForCompletedMotions;
+        controller.SetPosition(new Vector3(96f, 96f, 50f), 0x0001);
+        controller.Yaw = 0f; // heading 90 = facing +X
 
         var rig = new Rig { Controller = controller, MoveTo = null! };
         var moveTo = new MoveToManager(
@@ -270,6 +275,31 @@ public class PlayerMoveToCutoverTests
         Assert.True(result.MotionStateChanged);
     }
 
+    [Fact]
+    public void LoginQueue_DrainsToEmpty_UnderProductionFeed()
+    {
+        // The second live stall (2026-07-03, [autowalk-gate] probe): ONE
+        // immortal Ready node in pending_motions — login SetPosition's
+        // StopCompletely fired before the sink bind, orphaning its A9 node
+        // (no completable partner). Head-pop-any relabels but never empties
+        // a queue with an orphan, and MotionsPending==true wedges every
+        // subsequent moveto. This pins the invariant: after login (rig
+        // construction, production bind order) the queue must reach EMPTY
+        // under the production completion feed.
+        var rig = MakeRig(out var seq);
+        var c = rig.Controller;
+        seq.MotionDoneTarget = (m, ok) => c.Motion.MotionDone(m, ok);
+
+        for (int f = 0; f < 300 && c.Motion.MotionsPending(); f++)
+        {
+            c.Update(1f / 60f, new MovementInput());
+            seq.Advance(1f / 60f);
+        }
+
+        Assert.False(c.Motion.MotionsPending(),
+            "login pending_motions must drain to empty under the production feed");
+    }
+
     [Fact]
     public void ServerMoveToPosition_ProductionCompletionFeed_WalksToArrival()
     {

tests/AcDream.Core.Tests/Input/W6EdgeDrivenMovementTests.cs

@@ -95,15 +95,18 @@ public class W6EdgeDrivenMovementTests
     private static PlayerMovementController MakeControllerWithRealSink(out AnimationSequencer seq)
     {
         var controller = new PlayerMovementController(MakeFlatEngine());
-        controller.SetPosition(new Vector3(96f, 96f, 50f), 0x0001);
-        controller.Yaw = 0f;
         seq = MakeSequencer();
-        // The full W6 GameWindow bind set (EnterPlayerModeNow equivalent).
+        // The full W6 GameWindow bind set (EnterPlayerModeNow equivalent) —
+        // sink binds BEFORE SetPosition, matching the R4-V5 stall-fix order
+        // (SetPosition → StopCompletely needs the sink for its type-5
+        // dispatch, else its A9 pending_motions node is orphaned).
         controller.Motion.DefaultSink = new MotionTableDispatchSink(seq);
         var s = seq;
         controller.Motion.RemoveLinkAnimations = s.RemoveAllLinkAnimations;
         controller.Motion.InitializeMotionTables = () => s.Manager.InitializeState();
         controller.Motion.CheckForCompletedMotions = s.Manager.CheckForCompletedMotions;
+        controller.SetPosition(new Vector3(96f, 96f, 50f), 0x0001);
+        controller.Yaw = 0f;
         return controller;
     }