feat(system): enhance system architecture

internal/oscmd/oscmd.go

@@ -14,6 +14,7 @@ import (
 	"os/exec"
 	"strings"
 	"sync"
+	"syscall"
 	"time"
 )
 
@@ -276,6 +277,23 @@ func ParseKV(lines []string) map[string]string {
 	return m
 }
 
+// RunDetached starts name with args in a new process group (Setsid) and returns
+// immediately once the child has started. The child is reaped in the background
+// so it does not become a zombie.
+//
+// Use this for operations where the synchronous path would kill the caller
+// (e.g. "systemctl restart nadir" would SIGTERM the process serving the
+// request before the response is written).
+func RunDetached(name string, args ...string) (*StatusOutput, error) {
+	cmd := exec.Command(name, args...)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+	if err := cmd.Start(); err != nil {
+		return nil, err
+	}
+	go cmd.Wait()
+	return OK(), nil
+}
+
 // StatusOutput is the shared response for write operations that just report
 // success. Reusing one type means all such endpoints share a single OpenAPI
 // schema.