feat: port retail magic lifecycle and retained spell UI

Complete the retail cast-intent, target, component, enchantment, and busy-state paths; mount the DAT-authored spell bar, spellbook, component book, effects panels, and shared panel lifecycle; and add scoped input plus conformance coverage.

Co-Authored-By: Codex <noreply@openai.com>

tests/AcDream.App.Tests/Spells/RetailSpellTargetPolicyTests.cs

@@ -0,0 +1,115 @@
+using AcDream.App.Spells;
+using AcDream.Core.Items;
+using AcDream.Core.Spells;
+
+namespace AcDream.App.Tests.Spells;
+
+public sealed class RetailSpellTargetPolicyTests
+{
+    [Fact]
+    public void RejectsStackedTarget()
+    {
+        SpellTargetPolicyResult result = RetailSpellTargetPolicy.Evaluate(
+            1u,
+            new ClientObject { ObjectId = 2u, Name = "Scarabs", Type = ItemType.SpellComponents, StackSize = 2 },
+            Spell(targetMask: (uint)ItemType.SpellComponents));
+
+        Assert.False(result.Allowed);
+        Assert.Contains("stack", result.Message, StringComparison.OrdinalIgnoreCase);
+    }
+
+    [Fact]
+    public void RejectsSelfWithoutRetailSpecialTargetBits()
+    {
+        SpellTargetPolicyResult result = RetailSpellTargetPolicy.Evaluate(
+            1u,
+            new ClientObject { ObjectId = 1u, Name = "Self", Type = ItemType.Creature },
+            Spell(targetMask: (uint)ItemType.Creature));
+
+        Assert.False(result.Allowed);
+        Assert.Contains("yourself", result.Message, StringComparison.OrdinalIgnoreCase);
+    }
+
+    [Fact]
+    public void AcceptsSelfWithSpecialTargetBits()
+    {
+        SpellTargetPolicyResult result = RetailSpellTargetPolicy.Evaluate(
+            1u,
+            new ClientObject
+            {
+                ObjectId = 1u,
+                Name = "Self",
+                Type = ItemType.Creature,
+                PublicWeenieBitfield = (uint)PublicWeenieFlags.Player,
+            },
+            Spell(targetMask: 0x8101u));
+
+        Assert.True(result.Allowed);
+    }
+
+    [Theory]
+    [InlineData(PublicWeenieFlags.None, 0u, false)]
+    [InlineData(PublicWeenieFlags.Attackable, 0u, true)]
+    [InlineData(PublicWeenieFlags.Player, 0u, true)]
+    [InlineData(PublicWeenieFlags.Attackable, 99u, false)]
+    public void SpecialTargetBits_RequirePlayerOrAttackableNonPet(
+        PublicWeenieFlags flags,
+        uint petOwner,
+        bool expected)
+    {
+        SpellTargetPolicyResult result = RetailSpellTargetPolicy.Evaluate(
+            1u,
+            new ClientObject
+            {
+                ObjectId = 2u,
+                Name = "Target",
+                Type = ItemType.Creature,
+                PublicWeenieBitfield = (uint)flags,
+                PetOwnerId = petOwner,
+            },
+            Spell(targetMask: 0x8101u));
+
+        Assert.Equal(expected, result.Allowed);
+    }
+
+    [Fact]
+    public void RejectsTypeMaskMismatchWithObjectName()
+    {
+        SpellTargetPolicyResult result = RetailSpellTargetPolicy.Evaluate(
+            1u,
+            new ClientObject { ObjectId = 2u, Name = "Sword", Type = ItemType.MeleeWeapon },
+            Spell(targetMask: (uint)ItemType.Creature));
+
+        Assert.False(result.Allowed);
+        Assert.Contains("Sword", result.Message);
+    }
+
+    [Theory]
+    [InlineData(PublicWeenieFlags.Attackable, 0u, true)]
+    [InlineData(PublicWeenieFlags.None, 0u, false)]
+    [InlineData(PublicWeenieFlags.Player, 0u, true)]
+    [InlineData(PublicWeenieFlags.Attackable, 9u, false)]
+    public void DirectTypeMatch_StillRequiresPlayerOrAttackableNonPet(
+        PublicWeenieFlags flags,
+        uint petOwner,
+        bool expected)
+    {
+        SpellTargetPolicyResult result = RetailSpellTargetPolicy.Evaluate(
+            1u,
+            new ClientObject
+            {
+                ObjectId = 2u,
+                Name = "Target",
+                Type = ItemType.Misc,
+                PublicWeenieBitfield = (uint)flags,
+                PetOwnerId = petOwner,
+            },
+            Spell(targetMask: (uint)ItemType.Misc));
+
+        Assert.Equal(expected, result.Allowed);
+    }
+
+    private static SpellMetadata Spell(uint targetMask) => new(
+        1, "Test", "War Magic", 1, 0, "", 0, 0, false, false, "",
+        0, 0, 0, 1, false, false, false, 0, 0, 0, targetMask, 0);
+}