fix: Address code review for schema-booleans parser

- Align NeverSchema validator stub with the spec: keyword is now "false"
  and the rejected value is passed through via fail() instead of require()
- Drop residual Map cast in parseAdditionalProperties; parse(value) accepts
  Object directly so no unchecked cast is needed
- Static-import assertThatThrownBy in SchemaParserTest for consistency
  with the existing assertThat static import
- Add parsesArrayWithBooleanFalseItems test covering items: false -> NeverSchema
- Add rejectsNullRawSchema test covering null raw input -> IllegalArgumentException

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: thced

src/main/java/com/retailsvc/http/spec/schema/SchemaParser.java

@@ -139,7 +139,7 @@ private static AdditionalProperties parseAdditionalProperties(Object value) {
       case null -> new AdditionalProperties.Allowed();
       case Boolean b when b -> new AdditionalProperties.Allowed();
       case Boolean _ -> new AdditionalProperties.Forbidden();
-      default -> new AdditionalProperties.SchemaConstraint(parse((Map<String, Object>) value));
+      default -> new AdditionalProperties.SchemaConstraint(parse(value));
     };
   }
 

src/main/java/com/retailsvc/http/validate/DefaultValidator.java

@@ -67,7 +67,7 @@ case EnumSchema(List<Object> values) ->
       case ConstSchema(Object expected) ->
           require(Objects.equals(expected, value), pointer, "const", "value does not equal const");
       case AlwaysSchema _ -> {}
-      case NeverSchema _ -> require(false, pointer, "schema", "value rejected by false schema");
+      case NeverSchema _ -> fail(pointer, "false", "schema rejects all values", value);
       case OneOfSchema _ -> throw new UnsupportedOperationException("oneOf not yet supported");
       case AnyOfSchema _ -> throw new UnsupportedOperationException("anyOf not yet supported");
       case AllOfSchema _ -> throw new UnsupportedOperationException("allOf not yet supported");

src/test/java/com/retailsvc/http/spec/schema/SchemaParserTest.java

@@ -1,6 +1,7 @@
 package com.retailsvc.http.spec.schema;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 import java.util.List;
 import java.util.Map;
@@ -159,7 +160,7 @@ void parsesFalseAsNeverSchema() {
 
   @Test
   void rejectsNonMapNonBooleanRawSchema() {
-    org.assertj.core.api.Assertions.assertThatThrownBy(() -> SchemaParser.parse("oops"))
+    assertThatThrownBy(() -> SchemaParser.parse("oops"))
         .isInstanceOf(IllegalArgumentException.class)
         .hasMessageContaining("schema must be a boolean or an object");
   }
@@ -181,4 +182,18 @@ void parsesArrayWithBooleanItemsSchema() {
     assertThat(s).isInstanceOf(ArraySchema.class);
     assertThat(((ArraySchema) s).items()).isInstanceOf(AlwaysSchema.class);
   }
+
+  @Test
+  void parsesArrayWithBooleanFalseItems() {
+    Schema s = SchemaParser.parse(Map.of("type", "array", "items", Boolean.FALSE));
+    assertThat(s).isInstanceOf(ArraySchema.class);
+    assertThat(((ArraySchema) s).items()).isInstanceOf(NeverSchema.class);
+  }
+
+  @Test
+  void rejectsNullRawSchema() {
+    assertThatThrownBy(() -> SchemaParser.parse(null))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessageContaining("schema must be a boolean or an object");
+  }
 }