refactor(restart): extract stale pid cleanup and supervisor markers

src/infra/supervisor-markers.ts

@@ -0,0 +1,20 @@
+export const SUPERVISOR_HINT_ENV_VARS = [
+  // macOS launchd
+  "LAUNCH_JOB_LABEL",
+  "LAUNCH_JOB_NAME",
+  // OpenClaw service env markers
+  "OPENCLAW_LAUNCHD_LABEL",
+  "OPENCLAW_SYSTEMD_UNIT",
+  "OPENCLAW_SERVICE_MARKER",
+  // Linux systemd
+  "INVOCATION_ID",
+  "SYSTEMD_EXEC_PID",
+  "JOURNAL_STREAM",
+] as const;
+
+export function hasSupervisorHint(env: NodeJS.ProcessEnv = process.env): boolean {
+  return SUPERVISOR_HINT_ENV_VARS.some((key) => {
+    const value = env[key];
+    return typeof value === "string" && value.trim().length > 0;
+  });
+}