feat: add JoeAppEngine OPC UA nodes, fix DCL auto-reconnect and quality push

- Add JoeAppEngine folder to OPC UA nodes.json (BTCS, AlarmCntsBySeverity, Scheduler/ScanTime)
- Fix DataConnectionActor: capture Self in PreStart for use from non-actor threads,
  preventing Self.Tell failure in Disconnected event handler
- Implement InstanceActor.HandleConnectionQualityChanged to mark attributes Bad on disconnect
- Fix LmxFakeProxy TagMapper to serialize arrays as JSON instead of "System.Int32[]"
- Allow DataType and DataSourceReference updates in TemplateService.UpdateAttributeAsync
- Update test_infra_opcua.md with JoeAppEngine documentation

tests/ScadaLink.InboundAPI.Tests/InboundScriptExecutorTests.cs

@@ -17,7 +17,7 @@ public class InboundScriptExecutorTests
 
     public InboundScriptExecutorTests()
     {
-        _executor = new InboundScriptExecutor(NullLogger<InboundScriptExecutor>.Instance);
+        _executor = new InboundScriptExecutor(NullLogger<InboundScriptExecutor>.Instance, Substitute.For<IServiceProvider>());
         var locator = Substitute.For<IInstanceLocator>();
         var commService = Substitute.For<CommunicationService>(
             Microsoft.Extensions.Options.Options.Create(new CommunicationOptions()),
@@ -47,9 +47,10 @@ public class InboundScriptExecutorTests
     }
 
     [Fact]
-    public async Task UnregisteredHandler_ReturnsFailure()
+    public async Task UnregisteredHandler_InvalidScript_ReturnsCompilationFailure()
     {
-        var method = new ApiMethod("unknown", "return 1;") { Id = 1, TimeoutSeconds = 10 };
+        // Use an invalid script that cannot be compiled by Roslyn
+        var method = new ApiMethod("unknown", "%%% invalid C# %%%") { Id = 1, TimeoutSeconds = 10 };
 
         var result = await _executor.ExecuteAsync(
             method,
@@ -58,7 +59,22 @@ public class InboundScriptExecutorTests
             TimeSpan.FromSeconds(10));
 
         Assert.False(result.Success);
-        Assert.Contains("not compiled", result.ErrorMessage);
+        Assert.Contains("Script compilation failed", result.ErrorMessage);
+    }
+
+    [Fact]
+    public async Task UnregisteredHandler_ValidScript_LazyCompiles()
+    {
+        // Valid script that is not pre-registered triggers lazy compilation
+        var method = new ApiMethod("lazy", "return 1;") { Id = 1, TimeoutSeconds = 10 };
+
+        var result = await _executor.ExecuteAsync(
+            method,
+            new Dictionary<string, object?>(),
+            _route,
+            TimeSpan.FromSeconds(10));
+
+        Assert.True(result.Success);
     }
 
     [Fact]