test(secrets-cli): clean up temp dirs in TargetConfigReaderTests

ZB.MOM.WW.Secrets/tests/ZB.MOM.WW.Secrets.Tests/Cli/Interactive/TargetConfigReaderTests.cs

@@ -8,12 +8,26 @@ namespace ZB.MOM.WW.Secrets.Tests.Cli.Interactive;
 /// (base json + optional environment overlay + environment variables) exactly the way the app
 /// would at startup, so fixes land in the store the app actually reads.
 /// </summary>
-public sealed class TargetConfigReaderTests
+public sealed class TargetConfigReaderTests : IDisposable
 {
-    private static string NewTempDir()
+    private readonly List<string> _tempDirs = [];
+
+    public void Dispose()
+    {
+        foreach (string dir in _tempDirs)
+        {
+            if (Directory.Exists(dir))
+            {
+                try { Directory.Delete(dir, recursive: true); } catch (IOException) { /* best-effort temp cleanup */ }
+            }
+        }
+    }
+
+    private string NewTempDir()
     {
         string dir = Path.Combine(Path.GetTempPath(), "zb-secrets-cfg-" + Guid.NewGuid().ToString("N"));
         Directory.CreateDirectory(dir);
+        _tempDirs.Add(dir);
         return dir;
     }