- Add explicit 429 rate limit handling with RATE_LIMITED error code - Add 6 new test cases for edge scenarios: - 403 Forbidden handling - 429 Rate Limit handling - JSON parse error handling - WellNuo API failure when fetching beneficiary - Timeout error detection - MAC address uppercase normalization verification 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>