Fix prod Jenkins pipeline: add tests, restart, and health check stage

- Add Test stage (unit tests only) before migrations so bad code fails fast
- Add az webapp restart after async deploy to ensure new code is loaded
- Add Health Check stage that polls app for up to 3 minutes post-deploy
- Restore xcopy of wwwroot (needed for linux-x64 publish on Windows)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Jenkinsfile

@@ -24,6 +24,17 @@ pipeline {
             }
         }
 
+        stage('Test') {
+            steps {
+                bat 'dotnet test tests\\PowderCoating.UnitTests --no-build -c Release --logger "trx;LogFileName=results.trx" --results-directory TestResults'
+            }
+            post {
+                always {
+                    junit testResults: 'TestResults/*.trx', allowEmptyResults: true
+                }
+            }
+        }
+
         stage('Run Migrations') {
             steps {
                 bat 'dotnet tool install --global dotnet-ef 2>nul || dotnet tool update --global dotnet-ef 2>nul'
@@ -53,10 +64,37 @@ pipeline {
                     bat 'az login --service-principal -u "%AZ_CLIENT_ID%" -p "%AZ_CLIENT_SECRET%" --tenant "%AZ_TENANT_ID%" --output none'
                     bat 'az account set --subscription "%AZ_SUB_ID%"'
                     bat 'az webapp deploy --resource-group rg-powdercoatinglogix-prod --name linuxpcl --src-path deploy.zip --type zip --async true'
+                    bat 'az webapp restart --resource-group rg-powdercoatinglogix-prod --name linuxpcl'
                     bat 'az logout'
                 }
             }
         }
+
+        stage('Health Check') {
+            steps {
+                powershell '''
+                    $url = "https://linuxpcl.azurewebsites.net/"
+                    $timeout = 180
+                    $elapsed = 0
+                    Write-Host "Polling $url for up to $timeout seconds..."
+                    do {
+                        Start-Sleep -Seconds 10
+                        $elapsed += 10
+                        try {
+                            $r = Invoke-WebRequest $url -UseBasicParsing -TimeoutSec 10
+                            if ($r.StatusCode -lt 400) {
+                                Write-Host "App responded HTTP $($r.StatusCode) after ${elapsed}s"
+                                exit 0
+                            }
+                        } catch {
+                            Write-Host "[${elapsed}s] Not yet responding: $_"
+                        }
+                    } while ($elapsed -lt $timeout)
+                    Write-Error "App did not come healthy within $timeout seconds"
+                    exit 1
+                '''
+            }
+        }
     }
 
     post {