Architecture

How the service is structured and why. Roughly ordered C4-style — start at the top for the big picture and zoom in.

Doc	When you need it
Architecture style	Hexagonal layout, layer rules, why we picked this pattern
System context	The app and its external neighbours (LLM provider, Presidio, Postgres, callers)
Components	Ports, adapters, the orchestrator, the composition root
Cross-cutting concerns	Anonymisation, tracking, error handling, logging — concerns that span layers
Data model	Domain models and persistence schema

For decision history (why we chose what we chose), see the architecture decision records.