R106
A remote() call can't be made: no address, no WEFT_RUST_SECRET, or the sidecar refused the signature (503).
Fix: Set WEFT_RUST_<NAME>_URL and the same WEFT_RUST_SECRET on both sides. weft dev and weft start do it for what they supervise.
Status in weft@0.1.0: reported by @weft-js/start when it serves or renders the route, and by weft check and weft routes --meta.