Can't create a new workflow after creating Logic App through Foundry

### Severity

P1 - Critical (Blocking production)

### Describe the Bug with repro steps

I want to be able to add new workflows so I can extend the Azure DevOps MCP implementation. However, trying to create a new stateful workflow through the Azure Portal gives the following error;

Enabling logs gives the following error in Log Analytics;

```
Error message: correlationId='744706d2-c97a-4b5c-b02c-96ac3b82d990', operationName='ErrorResponseHandling.GetErrorResponseMessage.POST/RUNTIME/WORKFLOW/MANAGEMENT/SEND_HTTP_TEST/', message='Http request failed with unhandled exception of type 'NullReferenceException' and message: 'System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.Azure.Workflows.Data.Engines.FlowDefinitionValidationEngine.ValidateLimitedWorkflowApp(FlowPropertiesDefinition definition, String flowName)
at Microsoft.Azure.Workflows.Web.Engines.EdgeFlowWebManagementEngine.ValidateFlow(String appName, String flowName, FlowPropertiesDefinition flowPropertiesDefinition, EdgeConnectionReferencesDefinition edgeConnectionReferencesDefinition, Boolean isValidationRequest, InsensitiveDictionary`1 appSettings)
at Microsoft.Azure.Workflows.Web.Controllers.EdgeFlowController.<>c__DisplayClass1_0.<b__0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.Azure.Workflows.Templates.Engines.TemplateEngine.HandleTemplateException[T](Func`1 protectedMethod, HttpStatusCode statusCode)
at Microsoft.Azure.Workflows.Web.BaseFlowExtensionRouteInitializer.Invoke(HttpRequestMessage request, CancellationToken cancellationToken)
at Microsoft.Azure.Workflows.Web.Handlers.FlowExtensionHttpRequestHandler.HandleRequest(HttpRequestMessage request, CancellationToken cancellationToken)
at Microsoft.Azure.Workflows.Web.Handlers.FlowExtensionAuthorizationHandler.HandleRequest(HttpRequestMessage request, CancellationToken cancellationToken)
at Microsoft.Azure.Workflows.Web.Handlers.FlowExtensionErrorResponseHandler.HandleRequest(HttpRequestMessage request, CancellationToken cancellationToken)'.', exception='System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.Azure.Workflows.Data.Engines.FlowDefinitionValidationEngine.ValidateLimitedWorkflowApp(FlowPropertiesDefinition definition, String flowName)
at Microsoft.Azure.Workflows.Web.Engines.EdgeFlowWebManagementEngine.ValidateFlow(String appName, String flowName, FlowPropertiesDefinition flowPropertiesDefinition, EdgeConnectionReferencesDefinition edgeConnectionReferencesDefinition, Boolean isValidationRequest, InsensitiveDictionary`1 appSettings)
at Microsoft.Azure.Workflows.Web.Controllers.EdgeFlowController.<>c__DisplayClass1_0.<b__0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.Azure.Workflows.Templates.Engines.TemplateEngine.HandleTemplateException[T](Func`1 protectedMethod, HttpStatusCode statusCode)
at Microsoft.Azure.Workflows.Web.BaseFlowExtensionRouteInitializer.Invoke(HttpRequestMessage request, CancellationToken cancellationToken)
at Microsoft.Azure.Workflows.Web.Handlers.FlowExtensionHttpRequestHandler.HandleRequest(HttpRequestMessage request, CancellationToken cancellationToken)
at Microsoft.Azure.Workflows.Web.Handlers.FlowExtensionAuthorizationHandler.HandleRequest(HttpRequestMessage request, CancellationToken cancellationToken)
at Microsoft.Azure.Workflows.Web.Handlers.FlowExtensionErrorResponseHandler.HandleRequest(HttpRequestMessage request, CancellationToken cancellationToken)', organizationId='', activityVector='IN.0H.IN.02', additionalProperties='{"AFDCorrelationId":"Ref A: 3DA6BA7B09DC4E639D901C553002260A Ref B: AMS231032607039 Ref C: 2026-03-12T07:54:49Z","ParentActivityId":"00-47091c458140fa86c900b5f31509b10e-66e6d44237ce3f3d-01","X-Azure-JA4-Fingerprint":"t13d161100_7bcc74371b54_36bf25f296df"}', extensionVersion='1.160.9.0', siteName='logicapp-223056', slotName='Production', activityId='90785112-bafc-4afe-bac5-3e1e96d5be18'.
```

Steps to reproduce:

1. Go to Foundry portal - Build - Tools - Connect a Tool
2. Look up; Azure DevOps. This creates a new scaffolded Logic app (Foundry Preview)
3. Follow wizard and create logic app
4. In logic app, go to Workflows - Create - Stateful - enter name (Like test1). Error will be shown.

I expected to be able to add new workflows to extend the Azure DevOps MCP functionality in the logic app itself.

### What type of Logic App Is this happening in?

Standard (Portal)

### Are you experiencing a regression?

_No response_

### Which operating system are you using?

Windows

### Did you refer to the TSG before filing this issue? https://aka.ms/lauxtsg

Yes

### Workflow JSON

```json

```

### Screenshots or Videos

_No response_

### Environment

Browser: Edge Version 145.0.3800.97 (Official build) (64-bit)

### Additional context

_No response_