Router error messages are not great

[thockin]

$ curl -X POST -H "Host: ctr6.actors.resources.substrate.ate.dev" -i http://localhost:8888/
HTTP/1.1 500 Internal Server Error
content-type: 
content-length: 96
date: Thu, 21 May 2026 02:40:40 GMT
server: envoy

error resuming actor ctr6: rpc error: code = FailedPrecondition desc = no free workers available

$ curl -X POST -H "Host: ctr7.actors.resources.substrate.ate.dev" -i http://localhost:8888/
HTTP/1.1 404 Not Found
content-type: 
content-length: 9
date: Thu, 21 May 2026 02:40:46 GMT
server: envoy

not found