API Reference: Core Architectural Endpoints

1. Authentication

• POST /api/auth/login: Authenticates user credentials; returns JWT access token and sets refresh cookie.
• POST /api/auth/refresh: Validates refresh token and issues fresh access token.
• POST /api/auth/logout: Revokes current access token into Redis blacklist.

2. Transactions & Payments

• POST /api/transactions/transfer: Executes double-entry fund transfer inside an atomic ACID session.

3. Observability

• GET /metrics: Exposes Prometheus-compatible operational metrics (HTTP duration, event loop lag, memory RSS).
• GET /health: Readiness and liveness health probe.