Refactor subject conversion handling and enhance audit logging

- Replaced `Subject|array` return types with `SubjectBag` in `SubjectConverterInterface` for more robust handling.
- Updated `getSubjectsForEntity` to include an optional `$includeAssociated` parameter for finer control over associated subject resolution.
- Refactored `AuditEvent` to differentiate `mainSubject` from associated subjects, improving clarity in audit logging.
- Introduced database schema changes to add `main_subject` and `subjects` columns in the `chill_main_audit_trail` table.
- Added `SubjectBag` class for grouped subject management and implemented deduplication logic.
- Updated all converters and test cases to use the new `SubjectBag` approach, ensuring compatibility.
- Improved event dispatching in controllers to utilize the updated `AuditEvent` structure and refined metadata handling.

src/Bundle/ChillMainBundle/Audit/SubjectConverterManager.php

@@ -22,7 +22,7 @@ final readonly class SubjectConverterManager implements SubjectConverterManagerI
         private iterable $converters,
     ) {}
 
-    public function getSubjectsForEntity(mixed $subject): array
+    public function getSubjectsForEntity(mixed $subject, bool $includeAssociated = false): SubjectBag
     {
         foreach ($this->converters as $converter) {
             if ($converter instanceof SubjectConverterManagerAwareInterface) {
@@ -30,9 +30,7 @@ final readonly class SubjectConverterManager implements SubjectConverterManagerI
             }
 
             if ($converter->supportsConvert($subject)) {
-                $subjects = $converter->convert($subject);
-
-                return $subjects instanceof Subject ? [$subjects] : $subjects;
+                return $converter->convert($subject);
             }
         }