feat(vikon): add restoreAfterFail for crash recovery in FilesystemTask

app/Containers/VikonIntegration/Tasks/FilesystemTask.php

@@ -111,6 +111,44 @@ class FilesystemTask
         return $this->moveEntry($newEntryPath, $currentEntryPath, $isFile);
     }
 
+    public function restoreAfterFail(string $modulePath, array $allowedEntries, int $moduleId): bool
+    {
+        $entries = File::directories($modulePath);
+        $entries = array_merge($entries, File::files($modulePath));
+
+        foreach ($entries as $entryPath) {
+            $name = basename($entryPath);
+
+            if (str_ends_with($name, '_new')) {
+                $baseName = substr($name, 0, -4);
+                if (in_array($baseName, $allowedEntries, true)) {
+                    if (is_dir($entryPath)) {
+                        File::deleteDirectory($entryPath);
+                    } else {
+                        File::delete($entryPath);
+                    }
+                }
+            }
+
+            if (str_ends_with($name, '_old')) {
+                $baseName = substr($name, 0, -4);
+                if (in_array($baseName, $allowedEntries, true)) {
+                    $originalPath = $modulePath . '/' . $baseName;
+                    if (File::exists($originalPath)) {
+                        if (is_dir($originalPath)) {
+                            File::deleteDirectory($originalPath);
+                        } else {
+                            File::delete($originalPath);
+                        }
+                    }
+                    rename($entryPath, $originalPath);
+                }
+            }
+        }
+
+        return true;
+    }
+
     private function moveEntry(string $source, string $dest, bool $isFile): bool
     {
         if ($isFile) {

app/Containers/VikonIntegration/Tests/Unit/FilesystemTaskTest.php

@@ -82,4 +82,23 @@ class FilesystemTaskTest extends TestCase
 
         $this->assertFalse($result);
     }
+
+    public function test_restore_after_fail_removes_new_and_restores_old(): void
+    {
+        $base = $this->tempDir . '/module';
+        File::makeDirectory($base, 0755, true, true);
+
+        // Simulate partial swap state: _old has backup
+        File::makeDirectory($base . '/common', 0755, true, true);
+        file_put_contents($base . '/common/index.php', '<?php echo "current";');
+        File::makeDirectory($base . '/common_old', 0755, true, true);
+        file_put_contents($base . '/common_old/index.php', '<?php echo "original";');
+
+        $result = $this->fs->restoreAfterFail($base, ['common'], 1);
+
+        $this->assertTrue($result);
+        $this->assertFileExists($base . '/common/index.php');
+        $this->assertStringContainsString('original', file_get_contents($base . '/common/index.php'));
+        $this->assertDirectoryDoesNotExist($base . '/common_old');
+    }
 }