fix(cli(ups-handler), systemd): add type guards and null checks for UPS configs; improve SNMP handling and prompts; guard version display

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@serve.zone/nupst',
-  version: '5.2.0',
+  version: '5.2.1',
   description: 'Network UPS Shutdown Tool - Monitor SNMP-enabled UPS devices and orchestrate graceful system shutdowns during power emergencies'
 }