Function killByPidWithIdentity

design/src/daemon-client.ts:332–366

* Send SIGTERM (then SIGKILL) to `pid`, but ONLY if the running cmdline * contains `marker`. Prevents a stale state file from causing us to signal * an unrelated process that inherited the PID.

(
  pid: number,
  marker: string,
  verbose: boolean,
)

 * an unrelated process that inherited the PID.
 */
async function killByPidWithIdentity(
  pid: number,
  marker: string,
  verbose: boolean,
): Promise<void> {
  if (!pid || pid <= 0) return;
  if (!isProcessAlive(pid)) return;
  if (!verifyIdentity(pid, marker || CMDLINE_MARKER)) {
    log(
      verbose,
      `pid ${pid} is alive but cmdline doesn't match marker '${marker || CMDLINE_MARKER}'; skipping signal (possible PID reuse)`,
    );
    return;
  }
  try {
    process.kill(pid, "SIGTERM");
  } catch {
    // already gone
    return;
  }
  // Give it a grace period; SIGKILL if still alive AND still ours.
  const deadline = Date.now() + SIGTERM_GRACE_MS;
  while (Date.now() < deadline) {
    if (!isProcessAlive(pid)) return;
    await delay(50);
  }
  if (isProcessAlive(pid) && verifyIdentity(pid, marker || CMDLINE_MARKER)) {
    log(verbose, `pid ${pid} survived SIGTERM; SIGKILL`);
    try {
      process.kill(pid, "SIGKILL");
    } catch {
      // raced with exit
    }
  }
}

/**
 * Public: $D daemon stop. Posts /shutdown if no active boards; otherwise