Function set_expected_receiver_pid 

pub fn set_expected_receiver_pid(pid: pid_t)

Register the expected receiver PID for socket-based crash receivers.

When collect_all_threads is enabled and the receiver is reached via a Unix socket (not a forked child), the signal handler will only grant ptrace permission (PR_SET_PTRACER) if the socket peer’s PID (via SO_PEERCRED) matches this value.

Call this during trusted initialization (after connecting to or spawning the sidecar) with the sidecar’s PID

SAFETY: This function is safe to call from any context, its a single atomic store.