Correct the validation provider event order

docs/en/appendices/6-0-migration-guide.md

@@ -18,6 +18,10 @@ deprecation warnings.
 - `Cake\Event\Event::getSubject()` can now return `null` if the event has no
   subject instead of throwing an exception.
 
+- `Model.buildValidator` is now dispatched before the named validation method,
+  allowing listeners to register providers used by `Validator::add()`. Listeners
+  that inspect rules added by `validationDefault()` must account for this order.
+
 ## Breaking Changes
 
 ### Renamed Methods

docs/en/orm/table-objects.md

@@ -282,8 +282,10 @@ been replaced with the [Map Reduce](../orm/retrieving-data-and-resultsets#map-re
 
 `method` Cake\\ORM\\Table::**buildValidator**(EventInterface $event, Validator $validator, $name): void
 
-The `Model.buildValidator` event is fired when `$name` validator is created.
-Behaviors, can use this hook to add in validation methods.
+The `Model.buildValidator` event is fired when the `$name` validator is created,
+before the table's `validationDefault()` or other named validation method runs.
+Behaviors and other listeners can register providers here so that their rules
+are available when the validation method calls `Validator::add()`.
 
 ### buildRules
 

docs/en/orm/validation.md

@@ -35,8 +35,9 @@ When building an entity with validation enabled the following occurs:
 
 1. The validator object is created.
 2. The `table` and `default` validation provider are attached.
-3. The named validation method is invoked. For example `validationDefault`.
-4. The `Model.buildValidator` event will be triggered.
+3. The `Model.buildValidator` event is triggered, allowing behaviors and other
+   listeners to register validation providers.
+4. The named validation method is invoked. For example `validationDefault`.
 5. Request data will be validated.
 6. Request data will be type-cast into types that match the column types.
 7. Errors will be set into the entity.