45174ebe7d
Even with --api-addr set, mycelium also opens an internal JSON-RPC endpoint on 127.0.0.1:8990 by default (visible in --debug as \"Starting JSON-RPC server listen_addr=127.0.0.1:8990\"). When a previous run left an orphan mycelium running as root — which we can't SIGKILL from a user-level Child::kill_on_drop — the new instance fails to bind 8990 and exits ~10s after startup, with no sidecar://exited event because the kill never landed. Pin --metrics-api-address to a fresh ephemeral port alongside the other three. Known limitation: stopping the daemon still doesn't reliably kill the root child; the user has to `sudo pkill mycelium` between runs. Will be addressed by an elevated-shutdown hook.