Function pool 

pub async fn pool() -> PgPool

Connect to ares_test.

First call per test binary: connect, run migrations, truncate stale data. Every call returns a pool owned by the caller’s runtime — test binaries run many short-lived tokio runtimes, and a pool shared across them outlives the runtime it was created on. An unreachable database panics with fix instructions — live coverage is never silently skipped.