Fix ObjectBoxCache singleton to return existing cache object if already existing for path

lib/data/objectbox/objectbox_cache.dart

@@ -4,19 +4,29 @@ import 'package:logging/logging.dart';
 import 'package:path/path.dart' as p;
 import 'package:path_provider/path_provider.dart';
 
+import '../../globals.dart';
 import '../../objectbox.g.dart';
 
 class ObjectBoxCache {
   static final _logger = Logger('ObjectBoxCache');
+  static final _openCaches = <String, ObjectBoxCache>{};
   late final Store store;
 
   ObjectBoxCache._create(this.store);
 
-  static Future<ObjectBoxCache> create(
-      {String baseDir = 'objectboxcache', String? subDir}) async {
+  static Future<ObjectBoxCache> create({
+    String baseDir = 'objectboxcache',
+    String? subDir,
+  }) async {
     final docsDir = await getApplicationSupportDirectory();
 
     final path = p.join(docsDir.path, baseDir, subDir);
+    _logger.info('ObjectBoxCache path: $path');
+    if (_openCaches.containsKey(path)) {
+      _logger.fine('Cache already exists for path, returning it: $path');
+      return _openCaches[path]!;
+    }
+
     try {
       final directory = Directory(path);
       if (!directory.existsSync()) {
@@ -25,9 +35,14 @@ class ObjectBoxCache {
     } catch (e) {
       _logger.severe('Error creating ObjectCachePathDirectory: $e');
     }
-    _logger.info('ObjectBoxCache path: $path');
+
     final store = await openStore(
-        directory: path, macosApplicationGroup: 'T69YZGT58U.relatica');
-    return ObjectBoxCache._create(store);
+      directory: path,
+      macosApplicationGroup: macOsGroupId,
+    );
+    final cache = ObjectBoxCache._create(store);
+    _openCaches[path] = cache;
+    _logger.fine('New cache created for path: $path');
+    return cache;
   }
 }