Sets up the SDK_APP with a stable app ID for plugin testing (DEV only). Uses SDK_APP_ID and SDK_APP_API_KEY env vars so the app ID is fixed and predictable — plugins can hardcode it in their .env.test files. Configured with: - allowedOrigins: ['http://localhost:*'] (all localhost ports) - tenantSelfSignup: true - cloudViews: false Idempotent — safe to call on every test run. POST /account/test/playwright/setup-sdk-app Headers: x-playwright-api-key: <your-api-key> Body: { ownerEmail: string, ownerPassword?: string } Returns: { appId, domain, tenantId, userId, email, message }