Function augmented_path_var 

pub fn augmented_path_var() -> OsString

The ambient PATH plus the well-known install dirs that GUI/launchd parents omit (/opt/homebrew/bin, /usr/local/bin, ~/.local/bin).

MCP entries store the command as the user typed it (node, uvx, python3); which binary that names must not depend on WHO spawned the runtime. A terminal hands it the user’s full PATH and mur agent install-service derives a rich one into the unit file — but a Hub-spawned sidecar inherits the GUI’s minimal PATH, which is how command: node works in a shell and dies under the Hub with nothing pointing here. Ambient entries keep priority; only missing standard dirs are appended, so an explicit PATH override still wins.