Adds qt migration example

Jenkinsfile

@@ -0,0 +1,84 @@
+pipeline {
+  agent {
+    docker {
+      image 'lifemaps/ci-cpp:latest'
+      reuseNode true
+      args '-u root:root'
+    }
+  }
+
+  options {
+    timestamps()
+    disableConcurrentBuilds()
+  }
+
+  environment {
+    PROJECT_DIR = "qt6-after/qt6-migrated-benchmark"
+    BUILD_DIR = "build"
+    CHANGE_TARGET = "${env.CHANGE_TARGET ?: 'origin/main'}"
+  }
+
+  stages {
+    stage('Checkout') {
+      steps {
+        checkout scm
+        sh 'git fetch --all --prune'
+        sh 'git submodule update --init --recursive || true'
+      }
+    }
+
+    stage('Tool Versions') {
+      steps {
+        sh '''
+          python3 --version
+          cmake --version
+          ninja --version
+          g++ --version
+        '''
+      }
+    }
+
+    stage('Qt Diagnostics') {
+      steps {
+        sh '''
+          dpkg -l | grep -E "qt6-base-dev|qtbase5-dev|qt6-tools" || true
+          pkg-config --list-all | grep -i qt || true
+        '''
+      }
+    }
+
+    stage('Policy Checks') {
+      steps {
+        sh 'python3 ci/check_pr_policies.py'
+      }
+    }
+
+    stage('Configure') {
+      steps {
+        sh 'cmake -S ${PROJECT_DIR} -B ${BUILD_DIR} -G Ninja -DCMAKE_BUILD_TYPE=Debug'
+      }
+    }
+
+    stage('Build') {
+      steps {
+        sh 'cmake --build ${BUILD_DIR} --parallel'
+      }
+    }
+
+    stage('Test') {
+      steps {
+        sh 'ctest --test-dir ${BUILD_DIR} --output-on-failure'
+      }
+    }
+  }
+
+  post {
+    always {
+      script {
+        if (getContext(hudson.FilePath)) {
+          cleanWs deleteDirs: true, disableDeferredWipeout: true
+        }
+      }
+    }
+  }
+}