## Review: PASS ✓ Implementation matches technical spec: - Go 1.21 with PTY, WebSocket, terminal libs ✓ - ActionCable integration with auto-reconnect ✓ - Multi-stage Docker build integrated ✓ - Environment var configuration ✓ **Code quality**: Clean, readable, proper error handling. **Notes:** - No Go tests per user approval - Ready for end-to-end testing with live Rails WebSocket - Minor: PTY goroutines could use mutex for theoretical safety (not blocking)