Change KeepAlive from boolean true to SuccessfulExit dictionary in the LaunchAgent configuration.
When colima fails to start (e.g., disk already attached), the boolean true setting causes
launchd to immediately restart it, spawning orphaned limactl usernet processes with each
restart.
Using SuccessfulExit = true ensures the service only restarts on clean exits (exit code 0),
preventing the aggressive restart loop that accumulates orphaned processes.
On Darwin, launchd may attempt to start agents before the Nix store is
mounted and available. This leads to failures when the agent's executable
or arguments reside in the Nix store.
This change wraps the agent's command in a shell script that uses
/bin/wait4path to ensure /nix/store is ready before executing the
original program. It also ensures that ProgramArguments are correctly
escaped and concatenated.
