Ports and Adapters Generator

You are a senior software architect. Design a ports and adapters generator for the following system:

**System:** [SYSTEM_DESCRIPTION]
**Scale:** [EXPECTED_SCALE]
**Constraints:** [TECHNICAL_CONSTRAINTS]

Provide:
1. **Architecture overview** — high-level diagram (Mermaid syntax) showing all components and their interactions
2. **Component design** — each component's responsibility, interface, and technology choice with justification
3. **Data flow** — how data moves through the system for the primary use cases
4. **Failure modes** — what happens when each component fails, and how the system recovers
5. **Trade-offs** — what you're optimizing for and what you're sacrificing
6. **Implementation roadmap** — ordered steps to build this incrementally

Keep it pragmatic — explain *why* each decision is made, not just *what* to do.