feat: add email_test and email_test_result MCP tools}
- Add `email_test` tool to start live email deliverability tests (SPF, DKIM, DMARC, spam score, AI analysis) via POST endpoint - Add `email_test_result` tool to retrieve results of a previously started email test by testId via GET endpoint - Update tool count assertion in tests from 15 to 17 - Document email test flow and usage examples in README - Add v2026.4.114 changelog entry - Bump version to 2026.4.114 - Change project icon from 🌐 to 🔍 and add "code": "Probe" field