Fix integration test authentication and add README reference to copilot instructions

Co-authored-by: johlju <[email protected]>

Author: Copilot

.github/copilot-instructions.md

@@ -311,6 +311,10 @@ or later, after the Database Engine installation tests).
 When integration tests need the computer name in CI environments, always use 
 the Get-ComputerName command, which is available in the build pipeline.
 
+For integration testing commands use the information in the 
+tests/Integration/Commands/README.md, which describes the testing environment 
+including available instances, users, credentials, and other configuration details.
+
 All integration tests must use the below code block prior to the first
 `Describe`-block. The following code will set up the integration test
 environment and it will make sure the module being tested is available

tests/Integration/Commands/Assert-SqlLogin.Integration.Tests.ps1

@@ -37,7 +37,11 @@ Describe 'Assert-SqlLogin' -Tag @('Integration_SQL2016', 'Integration_SQL2017',
 
     Context 'When connecting to SQL Server instance' {
         BeforeAll {
-            $script:serverObject = Connect-SqlDscDatabaseEngine -InstanceName $script:instanceName
+            $script:sqlAdminCredential = New-Object -TypeName 'System.Management.Automation.PSCredential' -ArgumentList @(
+                'SqlAdmin',
+                ('P@ssw0rd1' | ConvertTo-SecureString -AsPlainText -Force)
+            )
+            $script:serverObject = Connect-SqlDscDatabaseEngine -InstanceName $script:instanceName -Credential $script:sqlAdminCredential
         }
 
         Context 'When a login exists' {