迁移 Flutter 端与训练脚本，模型/训练产物移出 git（遵循纯代码约定）

flutter_app/test/widget_test.dart

@@ -0,0 +1,37 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:observer/payment/models.dart';
+
+void main() {
+  test('LicenseStatus.isActive 未过期为 true', () {
+    final license = LicenseStatus(
+      active: true,
+      expiresAt: DateTime.now().add(const Duration(days: 1)),
+    );
+    expect(license.isActive, isTrue);
+  });
+
+  test('LicenseStatus.isActive 已过期为 false', () {
+    final license = LicenseStatus(
+      active: true,
+      expiresAt: DateTime.now().subtract(const Duration(days: 1)),
+    );
+    expect(license.isActive, isFalse);
+  });
+
+  test('LicenseStatus.isActive active=false 恒为 false', () {
+    final license = LicenseStatus(
+      active: false,
+      expiresAt: DateTime.now().add(const Duration(days: 1)),
+    );
+    expect(license.isActive, isFalse);
+  });
+
+  test('LicenseStatus.fromJson 解析', () {
+    final license = LicenseStatus.fromJson({
+      'active': true,
+      'expiresAt': '2026-08-29T23:59:59+08:00',
+    });
+    expect(license.active, isTrue);
+    expect(license.expiresAt, isNotNull);
+  });
+}