R106

A remote() call can't be made: no address, no KERF_RUST_SECRET, or the sidecar refused the signature (503).

Fix: Set KERF_RUST_<NAME>_URL and the same KERF_RUST_SECRET on both sides. kerf dev and kerf start do it for what they supervise.

Status in kerf@0.1.0: reported by @kerf-js/start when it serves or renders the route, and by kerf check and kerf routes --meta.