Initial commit: DLS - Dental Lab System

- Flutter + PocketBase dental lab management system
- Clinic & lab dashboards, job tracking, patient management
- Product catalog, finance tracking, multi-language support
- AI assistant integration, realtime notifications
- Windows installer (Inno Setup) included
- Developed by kovakyazilim.com

lib/core/services/realtime_service.dart

@@ -0,0 +1,37 @@
+import 'package:pocketbase/pocketbase.dart';
+import '../api/pocketbase_client.dart';
+
+typedef UnsubFn = Future<void> Function();
+
+class RealtimeService {
+  RealtimeService._();
+  static final instance = RealtimeService._();
+
+  final _pb = PocketBaseClient.instance.pb;
+
+  UnsubFn watch(
+    String collection, {
+    String topic = '*',
+    String filter = '',
+    required void Function(RecordSubscriptionEvent) onEvent,
+  }) {
+    UnsubFn? cancel;
+
+    _pb.collection(collection).subscribe(topic, onEvent, filter: filter).then((fn) {
+      cancel = fn;
+    });
+
+    return () async {
+      try {
+        final fn = cancel;
+        if (fn != null) {
+          await fn();
+        } else {
+          await _pb.collection(collection).unsubscribe(topic);
+        }
+      } catch (_) {
+        await _pb.collection(collection).unsubscribe(topic);
+      }
+    };
+  }
+}