fix(vendor): re-gate residuals — MaxStackSize is the stack operand, wire-authored use radius, purse summaries

R1 the split bar's operand is the item's authored MaxStackSize —
three retail sites read pwd._maxStackSize directly (InqListSlotCount
pc:200052, buy-button cases pc:203996/204086) where ACE never fills
the desc stack and standard stock is unlimited. Threaded StackSizeMax
end to end with one shared resolver; the two literal _maxStackSize
sites are now byte-exact; AP-165 retired, AP-169 corrected.
R2 walk-to-vendor never opened because GetUseRadius used an UNCITED
3m Creature heuristic as the local stop distance while ACE's poll
demands the authored radius (default 0.6 m) — the walk stopped and
the Use fired far outside acceptance. Now reads the wire-authored
spawn UseRadius with ACE's exact fallback; heuristic constants
deleted. A first sabotage attempt was non-discriminating
(coincidental 0.6) and was corrected — the discriminating version is
what landed.
R3 the Buying/Selling purse summaries ("Buying %d %s worth %hsp" /
"You have %hsp") recovered from the binary data segment where BN
mis-attributes the Buy-side literal; wired to staging and money
changes on the four authored text elements; AP-166 narrowed to the
pending-sell highlight.

Clean-room complete solution: 11,528 passed / 4 skipped / 0 failed.

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

tests/AcDream.App.Tests/UI/Layout/VendorUiControllerTests.cs

@@ -188,6 +188,11 @@ public sealed class VendorUiControllerTests
         public readonly UiButton BuyAllButton;
         public readonly UiButton BuyClearItemButton;
         public readonly UiButton BuyClearListButton;
+        // R3: the Buying/Selling tabs' own staged summary text.
+        public readonly UiText BuyListText = new();
+        public readonly UiText BuyPurseText = new();
+        public readonly UiText SellListText = new();
+        public readonly UiText SellPurseText = new();
         // Slice 6c: "Selling" tab staging widgets.
         public readonly UiItemList SellingList = new();
         public readonly UiButton SellItemButton;
@@ -280,11 +285,15 @@ public sealed class VendorUiControllerTests
             BuyingPage.AddChild(BuyAllButton);
             BuyingPage.AddChild(BuyClearItemButton);
             BuyingPage.AddChild(BuyClearListButton);
+            BuyingPage.AddChild(BuyListText);
+            BuyingPage.AddChild(BuyPurseText);
             SellingPage.AddChild(SellingList);
             SellingPage.AddChild(SellItemButton);
             SellingPage.AddChild(SellAllButton);
             SellingPage.AddChild(SellClearItemButton);
             SellingPage.AddChild(SellClearListButton);
+            SellingPage.AddChild(SellListText);
+            SellingPage.AddChild(SellPurseText);
 
             var layout = new ImportedLayout(root, new Dictionary<uint, UiElement>
             {
@@ -312,6 +321,10 @@ public sealed class VendorUiControllerTests
                 [VendorUiController.SellAllButtonId] = SellAllButton,
                 [VendorUiController.SellClearItemButtonId] = SellClearItemButton,
                 [VendorUiController.SellClearListButtonId] = SellClearListButton,
+                [VendorUiController.BuyingListTextId] = BuyListText,
+                [VendorUiController.BuyingPurseTextId] = BuyPurseText,
+                [VendorUiController.SellingListTextId] = SellListText,
+                [VendorUiController.SellingPurseTextId] = SellPurseText,
             });
 
             Window = RetailWindowFrame.Mount(
@@ -1199,6 +1212,36 @@ public sealed class VendorUiControllerTests
         Assert.Equal(25, h.Buys.Single().Amount);
     }
 
+    /// <summary>
+    /// R1 gate-finding fix, task item 5 (2026-08-08): an UNLIMITED-STOCK
+    /// item with no wire <c>DescStackSize</c> (the real ACE shape for a
+    /// browse-list row — see <see cref="VendorSplitPolicy.ResolveAuthoredStackSize"/>'s
+    /// doc comment) but a real <see cref="VendorShopItem.MaxStackSize"/>
+    /// (1000, matching the live retail screenshot's Prismatic Taper) must
+    /// still let the player buy an arbitrary quantity up to that ceiling —
+    /// the slider isn't merely decorative. This harness doesn't mount
+    /// <c>SelectedObjectController</c> (production's toolbar owns split
+    /// seeding), so it stands in for "the toolbar showed a ceiling of 1000
+    /// (MaxStackSize) and the player dragged to 300" by seeding
+    /// <see cref="Harness.SplitQuantity"/> directly with that SAME ceiling.
+    /// </summary>
+    [Fact]
+    public void BuyButton_Press_UnlimitedStockItemUsingMaxStackSizeCeiling_SendsTheSliderQuantity()
+    {
+        var h = new Harness();
+        h.State.Apply(VendorGuid, Profile(), new[]
+        {
+            new VendorShopItem(
+                StackedItemGuid, -1, 3u, "Prismatic Taper", (uint)ItemType.SpellComponents, 300u, 1000,
+                DescStackSize: null, MaxStackSize: 1000),
+        });
+        h.SplitQuantity.Reset(1000u, initialValue: 300u);
+
+        h.BuyButton.OnClick!.Invoke();
+
+        Assert.Equal(300, h.Buys.Single().Amount);
+    }
+
     [Fact]
     public void BuyButton_Press_NonStackedItem_IgnoresAStaleSliderFromAPreviouslySelectedStackableItem()
     {
@@ -1443,7 +1486,7 @@ public sealed class VendorUiControllerTests
         {
             new VendorShopItem(
                 StackedItemGuid, -1, 3u, "Arrows", (uint)ItemType.MissileWeapon, 300u, 1000,
-                DescStackSize: 100),
+                DescStackSize: 100, MaxStackSize: 100),
         });
         h.SplitQuantity.Reset(5000u, initialValue: 4990u);
         h.AddButton.OnClick!.Invoke();
@@ -2477,4 +2520,109 @@ public sealed class VendorUiControllerTests
 
         Assert.Equal(1, h.BuyingList.GetNumUIItems());
     }
+
+    // ══════════════════════════════════════════════════════════════════════
+    // R3 — the Buying/Selling tabs' own staged-count/total-value/purse text
+    // (grand-gate live evidence: retail's Buying tab shows "Buying 2 items
+    // worth 422p" / "You have 23p"; the strings are recovered byte-verbatim
+    // — see VendorUiController.BuildTransactionListText/BuildPurseText).
+    // ══════════════════════════════════════════════════════════════════════
+
+    [Fact]
+    public void BuyingTabSummaryText_TracksStagedCountValueAndPlayerPurse()
+    {
+        var h = new Harness();
+        h.State.Apply(VendorGuid, Profile(), new[]
+        {
+            new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 500),
+        });
+
+        // Before staging: zero staged count/value, still grammatically
+        // plural ("0 items"), purse text is live regardless of staging.
+        Assert.Equal("Buying 0 items worth 0p", GetText(h.BuyListText));
+        Assert.Equal($"You have {Harness.DefaultPlayerCoinValue:N0}p", GetText(h.BuyPurseText));
+
+        h.AddButton.OnClick!.Invoke();
+
+        // ComputeBuyTransactionValue: sellRate 1.5 * value 500 * quantity 1
+        // = 750, ceil(750 - 0.1) = 750.
+        Assert.Equal("Buying 1 item worth 750p", GetText(h.BuyListText));
+        Assert.Equal($"You have {Harness.DefaultPlayerCoinValue:N0}p", GetText(h.BuyPurseText));
+
+        h.BuyClearListButton.OnClick!.Invoke();
+
+        Assert.Equal("Buying 0 items worth 0p", GetText(h.BuyListText));
+    }
+
+    /// <summary>
+    /// R3: a money change with no staging change at all must still repaint
+    /// the purse line — retail's own purse text always reads the LIVE
+    /// holding, with no "did staging change" gate (see
+    /// <c>VendorUiController.OnObjectMoneyChanged</c>'s doc comment).
+    /// </summary>
+    [Fact]
+    public void BuyingTabPurseText_UpdatesOnAPlayerMoneyChangeAloneWithNoStagingChange()
+    {
+        var h = new Harness();
+        h.State.Apply(VendorGuid, Profile(), Array.Empty<VendorShopItem>());
+        Assert.Equal($"You have {Harness.DefaultPlayerCoinValue:N0}p", GetText(h.BuyPurseText));
+
+        var bundle = new PropertyBundle();
+        bundle.Ints[(uint)PropertyInt.CoinValue] = 42;
+        h.Objects.UpsertProperties(Harness.PlayerGuid, bundle);
+
+        Assert.Equal("You have 42p", GetText(h.BuyPurseText));
+        // Selling's purse text shares the SAME live holding read.
+        Assert.Equal("You have 42p", GetText(h.SellPurseText));
+    }
+
+    [Fact]
+    public void SellingTabSummaryText_TracksStagedCountValueAndPlayerPurse()
+    {
+        var h = new Harness();
+        h.State.Apply(VendorGuid, SellProfile((uint)ItemType.Armor), Array.Empty<VendorShopItem>());
+        MakePlayerOwned(h, PlayerOwnedArmorGuid, ItemType.Armor, 100);
+
+        Assert.Equal("Selling 0 items worth 0p", GetText(h.SellListText));
+        Assert.Equal($"You have {Harness.DefaultPlayerCoinValue:N0}p", GetText(h.SellPurseText));
+
+        h.Controller.HandleDropRelease(
+            h.SellingList, new UiItemSlot(), DragFromInventory(PlayerOwnedArmorGuid));
+
+        // ComputeSellTransactionValue: SellProfile's BuyPrice 1.0 * value
+        // 100 * quantity 1 = 100, floor(100 + 0.1) = 100.
+        Assert.Equal("Selling 1 item worth 100p", GetText(h.SellListText));
+        Assert.Equal($"You have {Harness.DefaultPlayerCoinValue:N0}p", GetText(h.SellPurseText));
+
+        h.SellClearListButton.OnClick!.Invoke();
+
+        Assert.Equal("Selling 0 items worth 0p", GetText(h.SellListText));
+    }
+
+    /// <summary>
+    /// Two staged units of the SAME stackable row: the count is the STAGED
+    /// QUANTITY total (2), not the row count (1) — matching the live
+    /// evidence screenshot's "Buying 2 items worth 422p" exactly (a single
+    /// stacked row, quantity 2).
+    /// </summary>
+    [Fact]
+    public void BuyingTabSummaryText_CountsStagedQuantityNotRowCountForAStackedItem()
+    {
+        var h = new Harness();
+        h.State.Apply(VendorGuid, Profile(), new[]
+        {
+            new VendorShopItem(
+                StackedItemGuid, -1, 3u, "Prismatic Taper", (uint)ItemType.SpellComponents, 300u, 1000,
+                DescStackSize: 100),
+        });
+        h.SplitQuantity.Reset(100u, initialValue: 2u);
+
+        h.AddButton.OnClick!.Invoke();
+
+        Assert.Equal(1, h.BuyingList.GetNumUIItems());
+        // ComputeBuyTransactionValue: perUnit = value 1000 / DescStackSize
+        // 100 = 10; sellRate 1.5 * perUnit 10 * quantity 2 = 30,
+        // ceil(30 - 0.1) = 30.
+        Assert.Equal("Buying 2 items worth 30p", GetText(h.BuyListText));
+    }
 }