Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: triceo

core/src/main/java/ai/timefold/solver/core/api/domain/common/PlanningId.java

@@ -24,7 +24,8 @@
  * {@link ValueRangeProvider planning value} class or any {@link ProblemFactCollectionProperty problem fact} class.
  * <p>
  * The return type can be any {@link Comparable} type which overrides {@link Object#equals(Object)} and
- * {@link Object#hashCode()}, and is usually {@link Long}, {@link UUID} or {@link String}.
+ * {@link Object#hashCode()}, or a primitive type whose boxed type implements {@link Comparable};
+ * it is usually {@link Long}, {@link UUID} or {@link String}.
  * It must never return a null instance.
  */
 @Target({ METHOD, FIELD })