Fix decimal boundary number handling

Author: Quahu

src/Laylua/Library/Marshaler/DefaultLuaMarshaler.TryGetValue.cs

@@ -472,7 +472,7 @@ private static bool TryConvertNumberValue(double value, Type clrType, LuaAllowed
 
         if (clrType == typeof(decimal))
         {
-            if (value is >= (double) decimal.MinValue and <= (double) decimal.MaxValue)
+            if (LuaTypeServices.IsDecimalValueInRange(value))
             {
                 result = (decimal) value;
                 return true;

src/Laylua/Library/Marshaler/LuaTypeServices.cs

@@ -361,7 +361,8 @@ internal static bool IsSingleValueInRange(lua_Number value)
     internal static bool IsDecimalValueInRange(lua_Number value)
     {
         return !double.IsNaN(value) && !double.IsInfinity(value)
-            && value is >= (double) decimal.MinValue and <= (double) decimal.MaxValue;
+            && value > (double) decimal.MinValue
+            && value < (double) decimal.MaxValue;
     }
 
     internal static Type NormalizeBoundaryType(Type type)

tests/Laylua.Tests/Tests/Marshaler/LuaMarshalerExplicitReadTests.cs

@@ -108,6 +108,20 @@ public void TryGetValue_DoubleToString_WithPrimitiveToString_Succeeds()
         Assert.That(value, Is.Not.Null.And.Not.Empty);
     }
 
+    [Test]
+    public void TryGetValue_DecimalBoundaryDouble_ReturnsFalseWithoutThrowing()
+    {
+        // Arrange
+        using var _ = Lua.Stack.SnapshotCount();
+        lua_pushnumber(L, (double) decimal.MaxValue);
+
+        var result = false;
+
+        // Act & Assert
+        Assert.That(() => result = Lua.Stack[1].TryGetValue(LuaAllowedValueConversions.None, out decimal _), Throws.Nothing);
+        Assert.That(result, Is.False);
+    }
+
     [Test]
     public void TryGetValue_SingleCharString_WithStringToChar_Succeeds()
     {

tests/Laylua.Tests/Tests/Marshaler/LuaTypeServicesTests.cs

@@ -554,6 +554,20 @@ public void GetImplicitCompatibilityCost_FloatToDecimal_ReturnsWideningCost()
         Assert.That(cost, Is.EqualTo((int) LuaMarshalingCompatibilityKind.NumericWidening));
     }
 
+    [Test]
+    public void GetImplicitCompatibilityCost_DecimalBoundaryDouble_WithRangeValidation_ReturnsIncompatible()
+    {
+        // Arrange
+        using var _ = Lua.Stack.SnapshotCount();
+        lua_pushnumber(L, (double) decimal.MaxValue);
+
+        // Act
+        var cost = GetCompatibilityCost(Lua, typeof(decimal), LuaAllowedValueConversions.None, validateNumericRange: true);
+
+        // Assert
+        Assert.That(cost, Is.EqualTo(-1));
+    }
+
     [Test]
     public void GetImplicitCompatibilityCost_FloatToDouble_ReturnsExactPrimitiveCost()
     {