feat: Initializes Objectbox database on startup

Integrates Objectbox database initialization into the main application startup process.

Adds `path` and `path_provider` as direct dependencies, which are typically required for Objectbox to locate the database directory.

lib/backend/objectbox/objectbox_manager.dart

@@ -0,0 +1,34 @@
+import 'dart:io';
+import 'package:path/path.dart' as p;
+import 'package:path_provider/path_provider.dart';
+
+import 'package:barcode_scanner/backend/objectbox/objectbox.g.dart';
+
+late ObjectboxManager objectboxManager;
+
+class ObjectboxManager {
+  /// The Store of this app.
+  late final Store store;
+
+  ObjectboxManager._create(this.store);
+
+  /// Create an instance of ObjectBox to use throughout the app.
+  static Future<ObjectboxManager> create() async {
+    Directory directory;
+    if (Platform.isIOS) {
+      directory = await getLibraryDirectory();
+    } else {
+      directory = await getApplicationSupportDirectory();
+    }
+    // Future<Store> openStore() {...} is defined in the generated objectbox.g.dart
+    final store = await openStore(
+      directory: p.join(directory.path, "objectbox_db"),
+    );
+    return ObjectboxManager._create(store);
+  }
+
+  /// Call it before `runApp()` in main.dart
+  static Future init() async {
+    objectboxManager = await ObjectboxManager.create();
+  }
+}

lib/services/service_initializer.dart

@@ -1,3 +1,4 @@
+import 'package:barcode_scanner/backend/objectbox/objectbox_manager.dart';
 import 'package:barcode_scanner/pages/login_page/login_page_model.dart';
 import 'package:barcode_scanner/provider_container.dart';
 import 'package:barcode_scanner/themes/app_theme.dart';
@@ -6,6 +7,7 @@ import 'package:flutter/foundation.dart';
 
 class InitializerService {
   static Future init() async {
+    await ObjectboxManager.init();
     await AppTheme.initialize();
     await providerContainer
         .read(loginPageModelProvider.notifier)

pubspec.lock

@@ -622,7 +622,7 @@ packages:
     source: hosted
     version: "2.2.0"
   path:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: path
       sha256: "75cca69d1490965be98c73ceaea117e8a04dd21217b37b292c9ddbec0d955bc5"
@@ -630,7 +630,7 @@ packages:
     source: hosted
     version: "1.9.1"
   path_provider:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: path_provider
       sha256: "50c5dd5b6e1aaf6fb3a78b33f6aa3afca52bf903a8a5298f53101fdaee55bbcd"

pubspec.yaml

@@ -52,6 +52,8 @@ dependencies:
   shared_preferences: ^2.5.3
   objectbox: ^4.3.0
   objectbox_flutter_libs: any
+  path_provider: ^2.1.5
+  path: ^1.9.1
 
 dev_dependencies:
   flutter_test: