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/AuditEvent2Trail.php

@@ -34,13 +34,10 @@ final readonly class AuditEvent2Trail implements AuditEvent2TrailInterface
             $event->description->trans($this->translator)
             : $event->description;
 
-        $subjects = array_reduce(
-            $event->subjects,
-            function (array $carry, mixed $item): array {
-                return array_merge($carry, $this->subjectConverterManager->getSubjectsForEntity($item));
-            },
-            []
-        );
+        $subjectBag = $this->subjectConverterManager->getSubjectsForEntity($event->mainSubject, true);
+        foreach ($event->subjects as $target) {
+            $subjectBag->append($this->subjectConverterManager->getSubjectsForEntity($target, false));
+        }
 
         $user = $this->security->getUser();
 
@@ -50,7 +47,8 @@ final readonly class AuditEvent2Trail implements AuditEvent2TrailInterface
             $this->clock->now(),
             $user instanceof User ? $user : null,
             $description,
-            array_map(fn (Subject $subject) => $subject->asArray(), $subjects),
+            $subjectBag->subject->asArray(),
+            array_map(fn (Subject $subject) => $subject->asArray(), $subjectBag->associatedSubjects),
             $event->metadata,
         );
     }