fix(vendor): evidence-based pass — max-first stack ceiling; the local player resolves never-animated MoveTo targets

Both chains pinned by the live [vendor-diag] run (vendor-diag.log)
after three code-reading rounds each failed:

The split bar: ACE serializes descStackSize=1 for EVERY browse row
(live wire, log 343-348) — the R1-era "ACE never populates desc"
claim is retracted with the line quoted. Retail's vendor sites read
pwd._maxStackSize directly (four sites, incl. UpdateItemsList
@0x004c1ea0 stamping min(remaining, _maxStackSize));
ResolveAuthoredStackSize flips to max-first for its vendor-only
consumers. Taper ceiling 1000, scarab 100, seed 1 for exempt.
Pricing still reads the desc (per-1 values on ACE).

Walk-to-use: the local player's getObjectA seam was bound to
TryGetPhysicsHost, which resolves only INSTALLED physics hosts — a
never-animated vendor has none, so TargetManager.SetTarget got null,
the MoveToObject armed with zero nodes, and UseTime never dispatched.
The log's natural=False completions were the user's own movement keys
(retail-correct input-edge cancels); attempt 4 worked because the
greeting animation had installed a host. RuntimePhysicsState gains
the retail CObjectMaint::GetObjectA seam (bound canonical resolver
with installed-host fallback); the graphical host binds the SAME
lazy-minimal-host resolver every remote already uses — whose own doc
comment names this exact never-animated hazard. The reservation
release was already correct (2b premise refuted with evidence); the
production-wiring invariants are now pinned by four new tests
including the pre-fix pathology as a permanent sabotage control.

AP-169 rewritten a second time, honestly. The [vendor-diag] probe
family (ACDREAM_DUMP_VENDOR) lands env-gated for future live triage.

Clean-room complete solution: 11,536 passed / 4 skipped / 0 failed.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/AcDream.App/Composition/SessionPlayerComposition.cs

@@ -509,6 +509,20 @@ internal sealed class SessionPlayerCompositionPhase
             d.PlayerIdentity,
             dormantLiveEntities,
             d.Options.DumpLiveSpawns ? d.Log : null);
+        // 2026-08-08 vendor-approach root cause: the local player's
+        // publication-chain host resolves moveto/sticky targets through
+        // RuntimePhysicsState.ResolveObjectTableHost. Bind the graphical
+        // host's canonical CObjectMaint::GetObjectA stand-in — the SAME
+        // lazy-minimal-host resolver every remote host's GetObjectA uses
+        // (LiveEntityMotionRuntimeController.ResolvePhysicsHost, reached
+        // through the deferred motion-bindings seam so this closure stays
+        // valid across session routes). Without it the local player's
+        // MoveToObject against a never-animated NPC/static object never
+        // received TargetManager.AddVoyeur's immediate initial snapshot and
+        // sat armed-but-inert forever (no nodes, no movement, no natural
+        // completion).
+        live.LiveEntities.Physics.BindObjectTableHostResolver(
+            guid => d.MotionBindings.ResolvePhysicsHost(guid));
         // C3c: the graphical first-entry drive controller — walks every
         // initial-Create residence through its Runtime conductor with the
         // production prepared-collision source, the live movement-skill

src/AcDream.App/Interaction/PlayerInteractionMovementSink.cs

@@ -1,4 +1,5 @@
 using AcDream.App.Input;
+using AcDream.Core.Items;
 using AcDream.Core.Physics;
 using AcDream.Core.Physics.Motion;
 
@@ -60,6 +61,14 @@ internal sealed class PlayerInteractionMovementSink(
             Height = approach.TargetHeight,
         };
 
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] BeginApproach guid=0x{approach.Target.ServerGuid:X8} "
+                + $"movementType={movement.Type} distanceToObject={parameters.DistanceToObject} "
+                + $"canCharge={parameters.CanCharge} target=0x{movement.ObjectId:X8}");
+        }
+
         // PerformMovement cancels at its head. Do it explicitly before the
         // intent is armed so cancellation of the preceding move cannot clear
         // the new request; the internal second call is then a retail no-op.

src/AcDream.App/Interaction/SelectionInteractionController.cs

@@ -173,10 +173,17 @@ internal sealed class SelectionInteractionController
         // Use. Equipped-child picking makes that click reachable, so the gate
         // ships with it.
         if (useImmediately && !_query.IsWieldedByPlayer(guid))
+        {
+            if (VendorDiagnostics.DumpVendorEnabled)
+            {
+                Console.WriteLine(
+                    $"[vendor-diag] route=dblclick-world PickAndStoreSelection guid=0x{guid:X8} enqueue=Activate");
+            }
             EnqueueIdentityBound(
                 RuntimeQueuedInteractionKind.Activate,
                 guid,
                 requireLiveEntity: true);
+        }
     }
 
     /// <summary>
@@ -205,6 +212,11 @@ internal sealed class SelectionInteractionController
             _toast?.Invoke("Nothing selected");
             return;
         }
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] route=keyboard-use UseCurrentSelection guid=0x{selected:X8} enqueue=Use");
+        }
         EnqueueIdentityBound(
             RuntimeQueuedInteractionKind.Use,
             selected,
@@ -260,10 +272,22 @@ internal sealed class SelectionInteractionController
         bool ownedByPlayer = _items.IsOwnedByPlayer(serverGuid);
         bool useable = ownedByPlayer || _query.IsUseable(serverGuid);
 
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] RequestUse entry guid=0x{serverGuid:X8} ownedByPlayer={ownedByPlayer} useable={useable}");
+        }
+
         if (useable
             && _query.TryGetApproach(serverGuid, out InteractionApproach approach)
             && !approach.IsCloseRange)
         {
+            if (VendorDiagnostics.DumpVendorEnabled)
+            {
+                Console.WriteLine(
+                    $"[vendor-diag] RequestUse guid=0x{serverGuid:X8} branch=approach-armed useRadius={approach.UseRadius} isCloseRange={approach.IsCloseRange}");
+            }
+
             // Genuinely out of range (a real walk, not just a turn) —
             // mirror SendPickup's arrival-gated shape: arm the transaction
             // on the approach token BEFORE the movement starts (so a
@@ -283,7 +307,17 @@ internal sealed class SelectionInteractionController
                             token.ControllerLifetime,
                             token.ApproachGeneration),
                         out _);
+                    if (VendorDiagnostics.DumpVendorEnabled)
+                    {
+                        Console.WriteLine(
+                            $"[vendor-diag] TryArmPostArrivalUse guid=0x{serverGuid:X8} armed={armed} approachToken=({token.ControllerLifetime},{token.ApproachGeneration})");
+                    }
                 });
+            if (VendorDiagnostics.DumpVendorEnabled)
+            {
+                Console.WriteLine(
+                    $"[vendor-diag] BeginApproach-result guid=0x{serverGuid:X8} started={started} armed={armed} stopDistance={approach.UseRadius} target=0x{approach.Target.ServerGuid:X8}");
+            }
             if (!started || !armed)
             {
                 // Release whatever got captured (or the caller's own
@@ -306,6 +340,11 @@ internal sealed class SelectionInteractionController
         // — keep retail's immediate send; ACE's own "already within use
         // distance" branch (Player_Move.cs:65-87) calls back synchronously,
         // so there is no arrival gap to race here.
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] RequestUse guid=0x{serverGuid:X8} branch=immediate-dispatch ownedByPlayer={ownedByPlayer} useable={useable}");
+        }
         RuntimeInteractionDispatchResult result =
             _transactions.TryDispatchUse(
                 serverGuid,
@@ -314,6 +353,11 @@ internal sealed class SelectionInteractionController
                 reservation,
                 _transport,
                 out uint sequence);
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] RequestUse guid=0x{serverGuid:X8} TryDispatchUse verdict={result} seq={sequence}");
+        }
         if (result == RuntimeInteractionDispatchResult.NotInWorld)
             _toast?.Invoke("Not in world");
         if (result == RuntimeInteractionDispatchResult.Dispatched)
@@ -545,6 +589,22 @@ internal sealed class SelectionInteractionController
         RuntimePendingUse pending,
         bool accepted)
     {
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            // Diagnostic-only re-query — TryGetApproach is a pure read with
+            // no side effects, so an extra call here (gated off in
+            // production) cannot change RequestUse's own dispatch outcome.
+            string distanceText = "n/a";
+            if (_query.TryGetApproach(pending.ServerGuid, out InteractionApproach diagApproach))
+            {
+                float dx = diagApproach.Target.Entity.Position.X - diagApproach.Player.Position.X;
+                float dy = diagApproach.Target.Entity.Position.Y - diagApproach.Player.Position.Y;
+                distanceText = MathF.Sqrt(dx * dx + dy * dy).ToString("F2");
+            }
+            Console.WriteLine(
+                $"[vendor-diag] HandleUseApproachCompletion guid=0x{pending.ServerGuid:X8} accepted={accepted} playerToTargetDist={distanceText}");
+        }
+
         if (!accepted)
         {
             pending.Reservation?.CancelBeforeDispatch();

src/AcDream.App/Interaction/WorldSelectionQuery.cs

@@ -567,8 +567,16 @@ internal sealed class WorldSelectionQuery
     /// within ACE's real UseRadius.
     /// </remarks>
     private float GetUseRadius(uint serverGuid)
-        => _liveEntities.TryGetSnapshot(serverGuid, out var spawn)
-            && spawn.UseRadius is > 0f
-                ? spawn.UseRadius.Value
-                : DefaultUseRadius;
+    {
+        bool haveSpawn = _liveEntities.TryGetSnapshot(serverGuid, out var spawn);
+        bool fromWire = haveSpawn && spawn.UseRadius is > 0f;
+        float radius = fromWire ? spawn.UseRadius!.Value : DefaultUseRadius;
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] GetUseRadius guid=0x{serverGuid:X8} radius={radius} "
+                + $"source={(fromWire ? "wire" : "fallback-0.6")}");
+        }
+        return radius;
+    }
 }

src/AcDream.App/UI/ItemInteractionController.cs

@@ -509,6 +509,11 @@ public sealed class ItemInteractionController : IDisposable
         switch (mode)
         {
             case InteractionModeKind.Use:
+                if (VendorDiagnostics.DumpVendorEnabled)
+                {
+                    Console.WriteLine(
+                        $"[vendor-diag] route=target-mode-click OfferPrimaryClick(Use) guid=0x{targetGuid:X8}");
+                }
                 ClearTargetMode();
                 accepted = ActivateItem(targetGuid);
                 break;
@@ -541,6 +546,11 @@ public sealed class ItemInteractionController : IDisposable
     /// </summary>
     public bool UseSelectedOrEnterMode(uint selectedObjectId)
     {
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] route=toolbar-or-queued-use UseSelectedOrEnterMode guid=0x{selectedObjectId:X8}");
+        }
         if (selectedObjectId != 0)
             return ActivateItem(selectedObjectId);
         return _interactionState.EnterUse();
@@ -640,6 +650,11 @@ public sealed class ItemInteractionController : IDisposable
 
     public bool ActivateItem(uint itemGuid)
     {
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] entry:ActivateItem guid=0x{itemGuid:X8} isTargetModeActive={IsTargetModeActive}");
+        }
         if (itemGuid == 0) return false;
 
         if (IsTargetModeActive)
@@ -966,6 +981,11 @@ public sealed class ItemInteractionController : IDisposable
     /// </summary>
     public bool ExecuteConfirmedUse(uint objectId)
     {
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] route=confirmed-use ExecuteConfirmedUse guid=0x{objectId:X8}");
+        }
         if (objectId == 0u || (_requestUse is null && _sendUse is null))
             return false;
         if (!EnsureInventoryRequestReady())

src/AcDream.App/UI/Layout/SelectedObjectController.cs

@@ -346,6 +346,13 @@ public sealed class SelectedObjectController : IRetainedPanelController
             ? $"{stackSize} {objectName}"
             : objectName;
 
+        if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] ApplySelection guid=0x{g:X8} stackSizeOperand={stackSize} "
+                + $"objectName={objectName ?? "null"} builtLabel={_currentName ?? "null"}");
+        }
+
         // ── 3. Selection overlay: brief flash (retail container ObjectSelected
         //       = Pause(0.25s)→Normal). "StackedItemSelected" for stacks. ──────────────
         SetOverlayState(stackSize > 1u
@@ -367,10 +374,23 @@ public sealed class SelectedObjectController : IRetainedPanelController
         // starting VALUE differs, not the ceiling.
         if (stackSize > 1u)
         {
-            uint seed = _isVendorSplitExempt(g) ? 1u : stackSize;
+            bool vendorSplitExempt = _isVendorSplitExempt(g);
+            uint seed = vendorSplitExempt ? 1u : stackSize;
             _splitQuantity.Reset(stackSize, initialValue: seed);
             if (_stackSizeEntry is not null) _stackSizeEntry.Visible = true;
             if (_stackSizeSlider is not null) _stackSizeSlider.Visible = true;
+            if (VendorDiagnostics.DumpVendorEnabled)
+            {
+                Console.WriteLine(
+                    $"[vendor-diag] ApplySelection guid=0x{g:X8} sliderVisible=true "
+                    + $"isVendorSplitExempt={vendorSplitExempt} maxSplitSize={stackSize} seed={seed}");
+            }
+        }
+        else if (VendorDiagnostics.DumpVendorEnabled)
+        {
+            Console.WriteLine(
+                $"[vendor-diag] ApplySelection guid=0x{g:X8} sliderVisible=false "
+                + $"failingPredicate=stackSize<=1u stackSize={stackSize}");
         }
 
         // ── 4. Health: query, and show the meter only if real health is already known.

src/AcDream.App/UI/Layout/VendorUiController.cs

@@ -1401,15 +1401,18 @@ public sealed class VendorUiController : IRetainedPanelController, IItemListDrag
     /// this one — otherwise the CURRENT slider value via
     /// <c>ItemHolder::GetObjectSplitSize</c> (<c>0x00586F00</c>).
     /// <para>
-    /// R1 gate-finding fix (2026-08-08, register AP-169 correction): the
-    /// ceiling this gates on is <see cref="VendorSplitPolicy.ResolveAuthoredStackSize"/>
-    /// — <see cref="VendorShopItem.DescStackSize"/> when the wire carries
-    /// it, else <see cref="VendorShopItem.MaxStackSize"/> — the SAME
-    /// resolution <see cref="VendorShopItemMaterializer"/> uses to seed
-    /// <see cref="ClientObject.StackSize"/> (and therefore the toolbar
-    /// slider's own ceiling, <c>SelectedObjectController</c>). Using a
-    /// narrower source here than the visible slider would let the slider
-    /// show a ceiling of 1000 while every Buy still sent quantity 1.
+    /// R1 gate-finding fix, CORRECTED at the 2026-08-08 live-evidence
+    /// re-fix (register AP-169, second correction): the ceiling this gates
+    /// on is <see cref="VendorSplitPolicy.ResolveAuthoredStackSize"/> —
+    /// <see cref="VendorShopItem.MaxStackSize"/> FIRST (retail's own
+    /// vendor-owned quantity operand: the Buy cases at
+    /// <c>pc:203996</c>/<c>204086</c> gate on <c>pwd._maxStackSize &gt; 1</c>
+    /// literally), falling back to <see cref="VendorShopItem.DescStackSize"/>
+    /// — the SAME resolution <see cref="VendorShopItemMaterializer"/> uses
+    /// to seed <see cref="ClientObject.StackSize"/> (and therefore the
+    /// toolbar slider's own ceiling, <c>SelectedObjectController</c>).
+    /// Using a narrower source here than the visible slider would let the
+    /// slider show a ceiling of 1000 while every Buy still sent quantity 1.
     /// </para>
     /// </summary>
     private uint ResolveBuyQuantity(VendorShopItem item)