diff --git a/integration_test/test_support.dart b/integration_test/test_support.dart
index 6f74a18b..698e4860 100644
--- a/integration_test/test_support.dart
+++ b/integration_test/test_support.dart
@@ -3,9 +3,9 @@ import 'dart:io';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
-import 'package:path_provider/path_provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:xworkmate/app/app.dart';
+import 'package:xworkmate/runtime/secure_config_store.dart';
 
 void initializeIntegrationHarness() {
   IntegrationTestWidgetsFlutterBinding.ensureInitialized();
@@ -13,15 +13,16 @@ void initializeIntegrationHarness() {
 
 Future<void> resetIntegrationPreferences() async {
   SharedPreferences.setMockInitialValues(<String, Object>{});
-  try {
-    final supportDirectory = await getApplicationSupportDirectory();
-    final xworkmateDirectory = Directory('${supportDirectory.path}/xworkmate');
-    if (await xworkmateDirectory.exists()) {
-      await xworkmateDirectory.delete(recursive: true);
+  final isolatedRoot = await Directory.systemTemp.createTemp(
+    'xworkmate-integration-store-',
+  );
+  debugOverridePersistentSupportRoot(isolatedRoot.path);
+  addTearDown(() async {
+    debugOverridePersistentSupportRoot(null);
+    if (await isolatedRoot.exists()) {
+      await isolatedRoot.delete(recursive: true);
     }
-  } catch (_) {
-    // Keep integration setup best-effort on runners without path support.
-  }
+  });
 }
 
 Future<void> pumpDesktopApp(
diff --git a/lib/runtime/file_store_support.dart b/lib/runtime/file_store_support.dart
index 174f0005..880af2c1 100644
--- a/lib/runtime/file_store_support.dart
+++ b/lib/runtime/file_store_support.dart
@@ -4,6 +4,15 @@ import 'dart:io';
 import 'package:path_provider/path_provider.dart';
 import 'package:yaml/yaml.dart';
 
+String? _persistentSupportRootOverride;
+
+void debugOverridePersistentSupportRoot(String? path) {
+  final trimmed = path?.trim() ?? '';
+  _persistentSupportRootOverride = trimmed.isEmpty
+      ? null
+      : normalizeStoreDirectoryPath(trimmed);
+}
+
 enum PersistentStoreScope { settings, tasks, secrets, audit }
 
 class PersistentWriteFailure {
@@ -120,6 +129,10 @@ class StoreLayoutResolver {
   }
 
   Future<String?> _defaultSupportRootPath() async {
+    final override = _persistentSupportRootOverride;
+    if (override != null && override.isNotEmpty) {
+      return override;
+    }
     try {
       final supportDirectory = await getApplicationSupportDirectory();
       return '${supportDirectory.path}/xworkmate';
diff --git a/test/runtime/app_controller_desktop_platform_suite.dart b/test/runtime/app_controller_desktop_platform_suite.dart
index f7e53077..c0155323 100644
--- a/test/runtime/app_controller_desktop_platform_suite.dart
+++ b/test/runtime/app_controller_desktop_platform_suite.dart
@@ -12,6 +12,8 @@ import 'package:xworkmate/runtime/desktop_platform_service.dart';
 import 'package:xworkmate/runtime/runtime_models.dart';
 import 'package:xworkmate/runtime/secure_config_store.dart';
 
+import '../test_support.dart';
+
 class _FakeDesktopPlatformService implements DesktopPlatformService {
   _FakeDesktopPlatformService()
     : _state = DesktopIntegrationState.fromJson(const <String, dynamic>{
@@ -104,8 +106,13 @@ class _FakeDesktopPlatformService implements DesktopPlatformService {
 }
 
 class _ThrowingSecureConfigStore extends SecureConfigStore {
-  _ThrowingSecureConfigStore()
-    : super(enableSecureStorage: false);
+  _ThrowingSecureConfigStore(String rootPath)
+    : super(
+        enableSecureStorage: false,
+        databasePathResolver: () async => '$rootPath/settings.sqlite3',
+        fallbackDirectoryPathResolver: () async => rootPath,
+        defaultSupportDirectoryPathResolver: () async => rootPath,
+      );
 
   @override
   Future<String?> loadGatewayToken({int? profileIndex}) async {
@@ -233,7 +240,10 @@ void main() {
     () async {
       SharedPreferences.setMockInitialValues(<String, Object>{});
       final service = _FakeDesktopPlatformService();
-      final controller = AppController(desktopPlatformService: service);
+      final controller = AppController(
+        store: createIsolatedTestStore(enableSecureStorage: false),
+        desktopPlatformService: service,
+      );
       addTearDown(controller.dispose);
 
       await _waitFor(() => !controller.initializing);
@@ -272,9 +282,19 @@ void main() {
     () async {
       SharedPreferences.setMockInitialValues(<String, Object>{});
       final server = await _FakeGatewayTestServer.start();
-      final controller = AppController(store: _ThrowingSecureConfigStore());
+      final tempDirectory = await Directory.systemTemp.createTemp(
+        'xworkmate-desktop-platform-tests-',
+      );
+      final controller = AppController(
+        store: _ThrowingSecureConfigStore(tempDirectory.path),
+      );
       addTearDown(server.close);
       addTearDown(controller.dispose);
+      addTearDown(() async {
+        if (await tempDirectory.exists()) {
+          await tempDirectory.delete(recursive: true);
+        }
+      });
 
       await _waitFor(() => !controller.initializing);
 
@@ -299,7 +319,7 @@ void main() {
 
 Future<void> _waitFor(
   bool Function() condition, {
-  Duration timeout = const Duration(seconds: 2),
+  Duration timeout = const Duration(seconds: 5),
 }) async {
   final stopwatch = Stopwatch()..start();
   while (!condition()) {
diff --git a/test/runtime/app_controller_navigation_favorites_suite.dart b/test/runtime/app_controller_navigation_favorites_suite.dart
index 6d815223..746eab19 100644
--- a/test/runtime/app_controller_navigation_favorites_suite.dart
+++ b/test/runtime/app_controller_navigation_favorites_suite.dart
@@ -8,12 +8,14 @@ import 'package:shared_preferences/shared_preferences.dart';
 import 'package:xworkmate/app/app_controller.dart';
 import 'package:xworkmate/models/app_models.dart';
 
+import '../test_support.dart';
+
 void main() {
   test(
     'AppController keeps tasks destination in focused destinations',
     () async {
       SharedPreferences.setMockInitialValues(<String, Object>{});
-      final controller = AppController();
+      final controller = AppController(store: createIsolatedTestStore());
       addTearDown(controller.dispose);
 
       await _waitFor(() => !controller.initializing);
@@ -43,7 +45,7 @@ void main() {
 
   test('AppController toggles focused navigation destinations', () async {
     SharedPreferences.setMockInitialValues(<String, Object>{});
-    final controller = AppController();
+    final controller = AppController(store: createIsolatedTestStore());
     addTearDown(controller.dispose);
 
     await _waitFor(() => !controller.initializing);