Switched internal Pod runtime spawning/restoration to typed `program + prefix_args` command resolution. Default runtime command now uses the current executable plus `pod`, while `INSOMNIA_POD_COMMAND` remains executable-only and not shell-parsed for development/debug overrides. `client::spawn_pod`, `SpawnPod`, and `RestorePod`/discovery restore paths use the typed command; detached process behavior and `INSOMNIA-READY` handshake are preserved. External review approved and validation passed. `insomnia-pod` packaging removal remains the next phase.
