feat: support Xorg & better auth logic (#80)

Co-authored-by: grialion <48643945+grialion@users.noreply.github.com>

src/signal_handler.c

@@ -0,0 +1,29 @@
+#include <errno.h>
+#include <stddef.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "signal_handler.h"
+
+static void handle_sigterm(int sig) {
+  (void)sig;
+
+  (void)signal(SIGTERM, SIG_IGN);
+  kill(-getpgrp(), SIGTERM);
+
+  int status;
+  while (waitpid(-1, &status, 0) > 0 || errno == EINTR) {
+  }
+
+  _exit(0);
+}
+
+void setup_sigterm() {
+  setpgid(0, 0);
+
+  struct sigaction sa;
+  sa.sa_handler = handle_sigterm;
+  sigemptyset(&sa.sa_mask);
+  sa.sa_flags = 0;
+  sigaction(SIGTERM, &sa, NULL);
+}