feat: implement headless server mode with API endpoints for metrics and process management

backend/sysinfo.go

@@ -313,6 +313,26 @@ func KillProcess(pid int32, force bool) error {
 	}
 	return p.Terminate()
 }
+// CollectFull gathers a complete metrics snapshot including GPU data.
+// Unlike NewSysInfo, it does not start a background emitter and does not
+// require a Wails runtime context — safe to call from server mode.
+func CollectFull(ctx context.Context) (*Metrics, error) {
+	s := &SysInfo{ctx: ctx}
+	m, err := s.CollectOnce()
+	if err != nil {
+		return nil, err
+	}
+	name, tot, used, util := queryGPU(ctx)
+	if name != "" {
+		m.GPUName = name
+		m.GPUTotal = tot
+		m.GPUUsed = used
+		m.GPUUtil = util
+		m.GPUProcesses = queryGPUProcesses(ctx)
+	}
+	return m, nil
+}
+
 // GetManPage returns the plain-text man page for the given command name.
 // Returns an empty string if man is not installed or the page does not exist.
 func GetManPage(name string) string {