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/ios/Flutter/Generated.xcconfig

@@ -0,0 +1,14 @@
+// This is a generated file; do not edit or check into version control.
+FLUTTER_ROOT=/opt/flutter
+FLUTTER_APPLICATION_PATH=/root/JustAMessenger/client
+COCOAPODS_PARALLEL_CODE_SIGN=true
+FLUTTER_TARGET=lib/main.dart
+FLUTTER_BUILD_DIR=build
+FLUTTER_BUILD_NAME=1.0.0
+FLUTTER_BUILD_NUMBER=1
+EXCLUDED_ARCHS[sdk=iphonesimulator*]=i386
+EXCLUDED_ARCHS[sdk=iphoneos*]=armv7
+DART_OBFUSCATION=false
+TRACK_WIDGET_CREATION=true
+TREE_SHAKE_ICONS=false
+PACKAGE_CONFIG=.dart_tool/package_config.json

client/ios/Flutter/flutter_export_environment.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+# This is a generated file; do not edit or check into version control.
+export "FLUTTER_ROOT=/opt/flutter"
+export "FLUTTER_APPLICATION_PATH=/root/JustAMessenger/client"
+export "COCOAPODS_PARALLEL_CODE_SIGN=true"
+export "FLUTTER_TARGET=lib/main.dart"
+export "FLUTTER_BUILD_DIR=build"
+export "FLUTTER_BUILD_NAME=1.0.0"
+export "FLUTTER_BUILD_NUMBER=1"
+export "DART_OBFUSCATION=false"
+export "TRACK_WIDGET_CREATION=true"
+export "TREE_SHAKE_ICONS=false"
+export "PACKAGE_CONFIG=.dart_tool/package_config.json"

client/ios/Runner/GeneratedPluginRegistrant.h

@@ -0,0 +1,19 @@
+//
+//  Generated file. Do not edit.
+//
+
+// clang-format off
+
+#ifndef GeneratedPluginRegistrant_h
+#define GeneratedPluginRegistrant_h
+
+#import <Flutter/Flutter.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface GeneratedPluginRegistrant : NSObject
++ (void)registerWithRegistry:(NSObject<FlutterPluginRegistry>*)registry;
+@end
+
+NS_ASSUME_NONNULL_END
+#endif /* GeneratedPluginRegistrant_h */

client/ios/Runner/GeneratedPluginRegistrant.m

@@ -0,0 +1,21 @@
+//
+//  Generated file. Do not edit.
+//
+
+// clang-format off
+
+#import "GeneratedPluginRegistrant.h"
+
+#if __has_include(<shared_preferences_foundation/SharedPreferencesPlugin.h>)
+#import <shared_preferences_foundation/SharedPreferencesPlugin.h>
+#else
+@import shared_preferences_foundation;
+#endif
+
+@implementation GeneratedPluginRegistrant
+
++ (void)registerWithRegistry:(NSObject<FlutterPluginRegistry>*)registry {
+  [SharedPreferencesPlugin registerWithRegistrar:[registry registrarForPlugin:@"SharedPreferencesPlugin"]];
+}
+
+@end