ikrame-ih/reckon-flow ? reverse-engineered prompt

Build me a headless backend for corporate travel approvals with a clean API and a real finance style workflow.

I want users to be able to create and review travel expenses, keep an immutable double entry ledger, upload receipts and have them turned into structured data, and then match expenses against bank transactions with smart reconciliation suggestions. Make writes safe to retry, so if the same request comes in twice it does not create duplicates. For sensitive actions, require an API key when configured.

Use a simple local setup that runs with a database, supports background processing for receipt extraction, and exposes Swagger docs plus a metrics endpoint. It should feel production ready, with request IDs, rate limiting, and solid error handling. If you need to look up current docs online for anything, do that. Also include a small demo seed so I can try the flow quickly after setup.