fix(phase2): Fix group deletion - use correct DeletionLogRepository method

Fixed Task 8 (Delete Group API):
- Changed deletionLogRepository.logDeletion() to createDeletionEntry()
- Use correct parameters matching DeletionLogRepository schema
- Deletion now works: group, images, files, consents all removed
- deletion_log entry created with proper data

Tested:
✅ Group deletion with valid token
✅ 404 for invalid/missing tokens
✅ Files deleted (original + preview)
✅ DB records deleted via CASCADE
✅ Deletion log entry created

All 8 Backend Management API tasks complete!

backend/src/routes/management.js

@@ -611,12 +611,13 @@ router.delete('/:token', async (req, res) => {
         await dbManager.run('DELETE FROM groups WHERE group_id = ?', [groupId]);
 
         // Create deletion_log entry
-        await deletionLogRepository.logDeletion({
+        await deletionLogRepository.createDeletionEntry({
             groupId: groupId,
-            deletedBy: 'user_self_service',
-            reason: 'User-initiated deletion via management token',
-            deletionDate: new Date().toISOString(),
-            imageCount: imageCount
+            year: groupData.year,
+            imageCount: imageCount,
+            uploadDate: groupData.uploadDate,
+            deletionReason: 'user_self_service_deletion',
+            totalFileSize: groupData.images.reduce((sum, img) => sum + (img.fileSize || 0), 0)
         });
 
         console.log(`✓ Group ${groupId} deleted via management token (${imageCount} images)`);