chore(test): add test infrastructure, CI config, and security scanning

- Add Jenkinsfile with E2E/visual regression/security scan stages
- Add Stryker mutation testing configuration
- Add security header scanning script (check-security-headers.ts)
- Remove old playwright.config.ts (migrated to e2e/playwright.config.ts)
- Remove obsolete .claude/skills/impeccable
- Update jest config for test path patterns
- Update package.json with comprehensive test scripts
- Update .gitignore for stryker-tmp/ and .pi/ temp files

e2e/playwright.config.ts

@@ -16,6 +16,7 @@ export default defineConfig({
   reporter: [
     ['html', { open: 'never' }],
     ['list', { printSteps: true }],
+    ['allure-playwright', { outputFolder: 'allure-results' }],
   ],
   snapshotDir: './visual-snapshots',
   snapshotPathTemplate: '{snapshotDir}/{projectName}/{testFilePath}/{arg}-{projectName}{ext}',