OHLC bar service: turns a price stream into bars, stores them in a durable Postgres/Timescale store (with a reference MariaDB store readable for comparison), and serves them read-only. Every route is an unauthenticated read of already-published bar data and CORS is open, so it must not be paired with cookies or bearer tokens without tightening that first. Timestamps are unix epoch in the store; there is no auth on this surface. Do not expose it on a public interface until that is settled.