feat: test result upload to mobilenext.ai

[gmegidish]

Summary

• Adds MobileNextTestResultConfig to DriverConfigMobileNext with uploadReport: 'on' | 'off' | 'on-failure', name, tags, and environment fields
• defineConfig() auto-injects MobileNextUploadReporter and a JSON reporter when the mobilenext driver has testResult.uploadReport set (not 'off')
• MobileNextUploadReporter tracks test failures during the run and in onEnd() copies JSON results and artifacts to a temp dir (stub — network upload to be implemented separately)

Usage

defineConfig({
  driver: {
    type: 'mobilenext',
    apiKey: process.env.MOBILENEXT_API_KEY,
    testResult: {
      uploadReport: 'on',          // or 'on-failure'
      name: 'Smoke suite',
      tags: ['nightly'],
      environment: 'staging',
    },
  },
});