sets SIGTERM death signal in each child before exec, so if the
daemon exits (even by crash/SIGKILL), all managed services receive
SIGTERM and terminate. adds libc dependency for prctl.
includes getppid() == 1 check to handle the fork/prctl race.
- start/stop/restart/status/logs/enable/disable/list/daemon
- PID-file based state, no daemon, no root
- config.toml with placeholders, restart policies, env vars
- log tailing with -n/-f and stderr colorization
- supervisor per service with SIGTERM handling
