fix(schema): enforce strict validation when converting property key values

The `convValue` method now utilizes `validValueOrThrow` to ensure
that any value which cannot be successfully normalized to the
PropertyKey's declared data type will explicitly throw an exception.
This prevents silent type mismatches or unexpected behavior and
reinforces type safety when handling property values, especially
after deserialization.

Author: dpol1

hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/PropertyKey.java

@@ -130,7 +130,7 @@ public Object defaultValue() {
         // value (e.g. Date) comes back as a String. Normalize it to the
         // runtime type expected by this property key's data type. Idempotent
         // for values already of the expected type.
-        Object normalized = this.validValue(value);
+        Object normalized = this.validValueOrThrow(value);
 
         // For SET cardinality, ensure we return a Set container and collapse duplicates
         if (this.cardinality == Cardinality.SET && normalized instanceof Collection) {

hugegraph-struct/src/main/java/org/apache/hugegraph/struct/schema/PropertyKey.java

@@ -135,7 +135,7 @@ public Object defaultValue() {
         // value (e.g. Date) comes back as a String. Normalize it to the
         // runtime type expected by this property key's data type. Idempotent
         // for values already of the expected type.
-        Object normalized = this.validValue(value);
+        Object normalized = this.validValueOrThrow(value);
 
         // For SET cardinality, ensure we return a Set container and collapse duplicates
         if (this.cardinality == Cardinality.SET && normalized instanceof Collection) {