test(electron): reap Windows process trees and retain smoke diagnostics

.github/workflows/build-and-make.yaml

@@ -1150,6 +1150,16 @@ jobs:
                       electron-backend-e2e:packaged-frame-copy-smoke \
                       --skip-nx-cache
 
+            - name: Upload packaged frame-copy smoke diagnostics
+              if: always() && matrix.os == 'linux' && matrix.linux_profile == 'portable'
+              uses: actions/upload-artifact@v7
+              with:
+                  name: packaged-frame-copy-smoke
+                  path: |
+                      dist/playwright-report/electron-backend-e2e/packaged-frame-copy-smoke/
+                      dist/test-results/electron-backend-e2e/packaged-frame-copy-smoke/
+                  retention-days: 7
+
             - name: Diagnose packaged x64 frame-copy hardware path
               if: matrix.os == 'linux' && matrix.linux_profile == 'portable'
               continue-on-error: true

.github/workflows/e2e-tests.yaml

@@ -68,6 +68,9 @@ jobs:
             - name: Build Backend
               run: pnpm nx build electron-backend
 
+            - name: Verify Electron process cleanup
+              run: pnpm exec tsx --test apps/electron-backend-e2e/src/performance/electron-process-termination.spec.ts
+
             - name: Install Playwright Browsers
               run: pnpm exec playwright install --with-deps