fix: T2A cooking works without a craft menu (#2693)

## Summary
With T2A packet crafting menus enabled (`t2aCraftMenus`, default for pre-UOTD eras), cooking did nothing. Double-clicking a Skillet set a target, and `T2ACraftSystem.ShowMenu` had no Cooking branch, so the target was accepted and silently dropped. Nothing else could cook either: the old RunUO "use food on a heat source" code was never hooked up and was removed in #1054.

T2A cooking never used a menu, so this restores the item-on-item / item-on-heat-source flow:

- **Per-item handling:** each ingredient (`CookableFood`, `Dough`, `SweetDough`, `SackFlour`, `BowlFlour`, `JarHoney`) implements `IT2ACombinable.TryCombine` and switches on the target. `T2ACooking` holds the shared target, water, combine and heat-timer helpers.
- **Heat source:** all `CookableFood` (raw meats, fish, eggs, unbaked pies/quiche/pizzas, cookie and cake mix), dough → bread loaf, sweet dough → muffins. One unit is used up at the start, then a 5 s timer; the Cooking check runs from `CookingLevel` to 100 (bread and muffins use `DefCooking`'s range). The food burns on failure or if the cook moves more than 3 tiles away.
- **Combinations:**
  - Open flour sack or bowl of flour + water → dough
  - Dough + pear / peach / apple / pumpkin / eggs / meat / sausage → the matching unbaked pie, quiche or pizza
  - Dough + honey → sweet dough
  - Sweet dough + honey → cookie mix
  - Flour + sweet dough → cake mix
  - The honey and flour + sweet dough recipes work in either direction.
- **Water:** water drinks (pitchers), buckets, barrels, tubs and trough add-ons, in the pack, in hand, or on the ground within 2 tiles and in line of sight.
- **Cooking tools are passive:** with T2A menus on, a tool whose system has no T2A menu (`T2ACraftSystem.HasMenu`) falls through to `ShowCraftMenu`, which does nothing under T2A. No dead target is left.

Behaviour with T2A menus off is unchanged.

## Follow-ups
- Static troughs/barrels and open water aren't water sources here or for pitcher filling (no static water ID list exists); to be fixed separately.
- Whether a bowl of flour returns an empty bowl is unconfirmed (`//TODO`).
- Cooking tools that must merely be in the pack for some recipes are not modelled yet.

## Testing
- `dotnet build`: 0 warnings, 0 errors
- New `T2ACookingTests`: flour + water, closed sack refused, dough + apple, honey in both directions, cookie mix, cake mix, wrong target consumes nothing, water in another player's pack refused
- Not covered: the heat timer (untested); not yet exercised in game

Projects/UOContent.Tests/Tests/Engines/Craft/T2ACookingTests.cs

@@ -0,0 +1,145 @@
+using Server;
+using Server.Items;
+using Server.Mobiles;
+using Xunit;
+
+namespace UOContent.Tests;
+
+[Collection("Sequential UOContent Tests")]
+public class T2ACookingTests
+{
+    private static PlayerMobile CreatePlayer()
+    {
+        var m = new PlayerMobile(World.NewMobile);
+        m.DefaultMobileInit();
+        m.MoveToWorld(new Point3D(4200, 500, 0), Map.Felucca);
+        m.AddItem(new Backpack());
+        return m;
+    }
+
+    [Fact]
+    public void FlourAndWaterPitcher_MakeDough()
+    {
+        var player = CreatePlayer();
+        var pack = player.Backpack;
+        var sack = new SackFlour { ItemID = 0x103A };
+        var pitcher = new Pitcher(BeverageType.Water);
+        pack.AddItem(sack);
+        pack.AddItem(pitcher);
+
+        var sackBefore = sack.Quantity;
+        var pitcherBefore = pitcher.Quantity;
+
+        Assert.True(sack.TryCombine(player, pitcher));
+        Assert.Equal(sackBefore - 1, sack.Quantity);
+        Assert.Equal(pitcherBefore - 1, pitcher.Quantity);
+        Assert.Equal(1, pack.GetAmount(typeof(Dough)));
+    }
+
+    [Fact]
+    public void ClosedFlourSack_IsRefused()
+    {
+        var player = CreatePlayer();
+        var sack = new SackFlour();
+        var pitcher = new Pitcher(BeverageType.Water);
+        player.Backpack.AddItem(sack);
+        player.Backpack.AddItem(pitcher);
+
+        Assert.False(sack.TryCombine(player, pitcher));
+        Assert.Equal(20, sack.Quantity);
+        Assert.Equal(pitcher.MaxQuantity, pitcher.Quantity);
+        Assert.Equal(0, player.Backpack.GetAmount(typeof(Dough)));
+    }
+
+    [Fact]
+    public void DoughAndApple_MakeUnbakedApplePie()
+    {
+        var player = CreatePlayer();
+        var dough = new Dough();
+        var apple = new Apple();
+        player.Backpack.AddItem(dough);
+        player.Backpack.AddItem(apple);
+
+        Assert.True(dough.TryCombine(player, apple));
+        Assert.Equal(1, player.Backpack.GetAmount(typeof(UnbakedApplePie)));
+        Assert.Equal(0, player.Backpack.GetAmount(typeof(Apple)));
+        Assert.Equal(0, player.Backpack.GetAmount(typeof(Dough)));
+    }
+
+    [Fact]
+    public void HoneyRows_WorkInEitherDirection()
+    {
+        var player = CreatePlayer();
+        var pack = player.Backpack;
+        var dough = new Dough();
+        var honey = new JarHoney();
+        pack.AddItem(dough);
+        pack.AddItem(honey);
+        Assert.True(dough.TryCombine(player, honey));
+        Assert.Equal(1, pack.GetAmount(typeof(SweetDough)));
+
+        var dough2 = new Dough();
+        var honey2 = new JarHoney();
+        pack.AddItem(dough2);
+        pack.AddItem(honey2);
+        Assert.True(honey2.TryCombine(player, dough2));
+        Assert.Equal(2, pack.GetAmount(typeof(SweetDough)));
+
+        var sweet = pack.FindItemByType<SweetDough>();
+        var honey3 = new JarHoney();
+        pack.AddItem(honey3);
+        Assert.True(sweet.TryCombine(player, honey3));
+        Assert.Equal(1, pack.GetAmount(typeof(CookieMix)));
+    }
+
+    [Fact]
+    public void WrongTarget_ConsumesNothing()
+    {
+        var player = CreatePlayer();
+        var dough = new Dough();
+        var honey = new JarHoney();
+        player.Backpack.AddItem(dough);
+        player.Backpack.AddItem(honey);
+        var apple = new Apple();
+        player.Backpack.AddItem(apple);
+
+        var pitcher = new Pitcher(BeverageType.Water);
+        player.Backpack.AddItem(pitcher);
+
+        Assert.False(honey.TryCombine(player, apple));
+        Assert.False(dough.TryCombine(player, pitcher));
+        Assert.Equal(1, player.Backpack.GetAmount(typeof(Dough)));
+        Assert.Equal(1, player.Backpack.GetAmount(typeof(JarHoney)));
+        Assert.Equal(1, player.Backpack.GetAmount(typeof(Apple)));
+    }
+
+    [Fact]
+    public void BowlFlourAndSweetDough_MakeCakeMix()
+    {
+        var player = CreatePlayer();
+        var bowl = new BowlFlour();
+        var sweetDough = new SweetDough();
+        player.Backpack.AddItem(bowl);
+        player.Backpack.AddItem(sweetDough);
+
+        Assert.True(sweetDough.TryCombine(player, bowl));
+        Assert.True(bowl.Deleted);
+        Assert.True(sweetDough.Deleted);
+        Assert.Equal(1, player.Backpack.GetAmount(typeof(CakeMix)));
+    }
+
+    [Fact]
+    public void WaterInAnotherPlayersPack_IsRefused()
+    {
+        var player = CreatePlayer();
+        var other = CreatePlayer();
+        var sack = new SackFlour { ItemID = 0x103A };
+        var pitcher = new Pitcher(BeverageType.Water);
+        player.Backpack.AddItem(sack);
+        other.Backpack.AddItem(pitcher);
+
+        Assert.False(sack.TryCombine(player, pitcher));
+        Assert.Equal(20, sack.Quantity);
+        Assert.Equal(pitcher.MaxQuantity, pitcher.Quantity);
+    }
+}