Remove 'no vendor' negative tests and names

Remove 'no vendor' negative test cases and their step name constants. Deleted Create400NoVendor and Update400NoVendor from DotNet/Automation.UI/Services/ApiHealth/TestSuites/ApiEndPointLibrary.cs and removed the corresponding test steps from DotNet/Automation.UI/Services/ApiHealth/TestSuites/TenantServiceTestSuite.cs. Cleans up unused step names and obsolete negative test cases; no other behavior changes.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: johnbritton

DotNet/Automation.UI/Services/ApiHealth/TestSuites/ApiEndPointLibrary.cs

@@ -406,7 +406,6 @@ public static class TenantSteps
     {
         public const string Create201 = "Create → 201";
         public const string Create400Duplicate = "Create → 400 (duplicate)";
-        public const string Create400NoVendor = "Create → 400 (no vendor)";
         public const string Create400NoName = "Create → 400 (no name)";
         public const string Search200 = "Search → 200";
         public const string Search204NoResults = "Search → 204 (no results)";
@@ -416,7 +415,6 @@ public static class TenantSteps
         public const string Get404 = "Get → 404";
         public const string Update200 = "Update → 200";
         public const string Update404NonExistent = "Update → 404 (non-existent)";
-        public const string Update400NoVendor = "Update → 400 (no vendor)";
         public const string CheckExists200 = "CheckExists → 200";
         public const string CheckExists404 = "CheckExists → 404";
         public const string SoftDelete204 = "SoftDelete → 204";

DotNet/Automation.UI/Services/ApiHealth/TestSuites/TenantServiceTestSuite.cs

@@ -100,10 +100,6 @@ AdHocReportRequest BuildAdhoc(
             results.Add(await RunStepAsync(StepNames.Create400Duplicate, 400, async () =>
                 await _client.CreateAsync(BuildFacility(facilityId, vendor: testVendor), ct), ct: ct));
 
-            // Create → 400 (no vendor)
-            results.Add(await RunStepAsync(StepNames.Create400NoVendor, 400, async () =>
-                await _client.CreateAsync(BuildFacility($"ApiHealth-NoVendor-{Guid.NewGuid():N}", "NoVendor", null), ct), ct: ct));
-
             // Create → 400 (no name)
             results.Add(await RunStepAsync(StepNames.Create400NoName, 400, async () =>
                 await _client.CreateAsync(BuildFacility($"ApiHealth-NoName-{Guid.NewGuid():N}", name: null, allowNullName: true, vendor: testVendor), ct), ct: ct));
@@ -187,10 +183,6 @@ AdHocReportRequest BuildAdhoc(
             results.Add(await RunStepAsync(StepNames.Update404NonExistent, 404, async () =>
                 await _client.UpdateAsync(fakeFacilityId, BuildFacility(fakeFacilityId), ct), ct: ct));
 
-            // Update → 400 (no vendor)
-            results.Add(await RunStepAsync(StepNames.Update400NoVendor, 400, async () =>
-                await _client.UpdateAsync(facilityId, BuildFacility(facilityId, vendor: null), ct), ct: ct));
-
             // === GET /api/Facility/{id} (exists check) ===
 
             // CheckExists → 200