fix(ui): reuse shared file path picker for script settings (#1496)

ui/flutter/test/shared/widgets/app_path_picker_field_test.dart

@@ -0,0 +1,39 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:gopeed/shared/theme/app_component_themes.dart';
+import 'package:gopeed/shared/theme/app_theme.dart';
+import 'package:gopeed/shared/widgets/app_path_picker_field.dart';
+import 'package:gopeed/shared/widgets/app_text_field.dart';
+import 'package:shadcn_flutter/shadcn_flutter.dart' as shad;
+
+void main() {
+  testWidgets('file paths remain editable and Web hides native file selection', (tester) async {
+    final controller = TextEditingController(text: '/scripts/old.sh');
+    addTearDown(controller.dispose);
+
+    await tester.pumpWidget(
+      shad.ShadcnApp(
+        theme: AppTheme.light(),
+        materialTheme: AppTheme.materialLight(),
+        home: AppComponentThemes(
+          child: Center(
+            child: AppPathPickerField.file(
+              controller: controller,
+              desktopWidth: 320,
+              pickerKey: const ValueKey('file-picker'),
+            ),
+          ),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    expect(find.byKey(const ValueKey('file-picker')), kIsWeb ? findsNothing : findsOneWidget);
+    expect(tester.widget<AppTextField>(find.byType(AppTextField)).readOnly, isFalse);
+    await tester.enterText(find.byType(EditableText), '/scripts/custom.sh');
+    await tester.pump();
+    expect(controller.text, '/scripts/custom.sh');
+    expect(tester.takeException(), isNull);
+  });
+}