сборка: APK (Android) + Linux Desktop

- Исправлены ошибки Flutter анализа (withOpacity, pbkdf2, импорты)
- Упрощён pubspec.yaml (только нужные зависимости)
- Android APK собран: build/app/outputs/flutter-apk/app-release.apk (22MB)
- Linux Desktop собран: build/linux/x64/release/bundle/jam_client

Для Windows: кросс-компиляция невозможна с Linux.
Нужен Windows хост для flutter build windows.

client/pubspec.yaml

@@ -1,10 +1,10 @@
 name: jam_client
 description: JustAMessenger - Lightweight Decentralized Messenger
 publish_to: 'none'
-version: 0.1.0+1
+version: 1.0.0+1
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.5.4
 
 dependencies:
   flutter:
@@ -15,31 +15,15 @@ dependencies:
   web_socket_channel: ^3.0.1
   provider: ^6.1.2
   shared_preferences: ^2.3.3
-  file_picker: ^8.1.6
-  image_picker: ^1.1.2
-  permission_handler: ^11.3.1
   crypto: ^3.0.6
-  path_provider: ^2.1.4
-  sqflite: ^2.4.0
-  intl: ^0.19.0
-  audioplayers: ^6.1.0
-  record: ^5.2.0
-  video_player: ^2.9.2
-  flutter_svg: ^2.0.17
-  cached_network_image: ^3.4.1
-  photo_view: ^0.15.0
-  emoji_picker_flutter: ^4.3.2
-  flutter_webrtc: ^0.11.7
+  http: ^1.2.2
+  http_parser: ^4.0.2
   mime: ^2.0.0
-  http_parser: ^4.1.0
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  flutter_lints: ^5.0.0
+  flutter_lints: ^4.0.0
 
 flutter:
   uses-material-design: true
-  assets:
-    - assets/icons/
-    - assets/stickers/