feat(otopcua): add ITagDiscovery.RediscoverPolicy + per-driver assignments (follow-up B)

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests/FocasScaffoldingTests.cs

@@ -203,6 +203,18 @@ public sealed class FocasScaffoldingTests
         drv.DriverInstanceId.ShouldBe("drv-1");
     }
 
+    /// <summary>
+    ///     Verifies FOCAS opts into retry-until-stable post-connect re-discovery — its
+    ///     FixedTree subtree is populated asynchronously by a background loop a couple of
+    ///     seconds after connect, so a single DiscoverAsync pass would miss it.
+    /// </summary>
+    [Fact]
+    public void RediscoverPolicy_is_UntilStable()
+    {
+        var drv = new FocasDriver(new FocasDriverOptions(), "drv-1");
+        drv.RediscoverPolicy.ShouldBe(DiscoveryRediscoverPolicy.UntilStable);
+    }
+
     /// <summary>Verifies InitializeAsync parses device addresses correctly.</summary>
     [Fact]
     public async Task InitializeAsync_parses_device_addresses()