SYMPHONY is a clinic-oriented digital twin application designed for structured exploration of longitudinal neurological data. The system provides deterministic clinical risk computation, progression visualization, and formalized report export within a governed browser-based environment. It is implemented as a modular React application with a supporting Node-based server layer responsible for authentication scaffolding, security hardening, and electronic health record (EHR) connectivity abstraction. The current implementation supports structured ingestion of patient data, deterministic transformation through validated numerical utilities, interactive visualization of trajectories, and client-side generation of formal PDF reports. The system is designed to preserve source data integrity and to ensure that computed outputs are reproducible, testable, and version controlled. The intended use is structured clinical reasoning and reporting within a controlled environment suitable for research demonstration, methodological validation, and institutional review.