Version-requirements Memes

Nothing says "mature enterprise application" quite like requiring PostgreSQL 18+ access. You know, the version that doesn't exist yet since we're currently at PostgreSQL 16. Either this project is so cutting-edge it's time-traveling, or someone's README is living in a very optimistic future. The Rust toolchain requirement is appropriately stable though, so at least half the prerequisites are grounded in reality. Props for the age-gating on databases—wouldn't want any underage MySQL instances sneaking in.