feat(snmp): add configurable SNMP runtime units with v4.3 migration support

ts/cli/ups-handler.ts

@@ -974,6 +974,35 @@ export class UpsHandler {
         OUTPUT_CURRENT: '',
       };
     }
+
+    // Runtime unit selection
+    logger.log('');
+    logger.info('Battery Runtime Unit:');
+    logger.dim('  Controls how NUPST interprets the runtime value from your UPS.');
+    logger.dim('  1) Minutes (APC, TrippLite, Liebert - most common)');
+    logger.dim('  2) Seconds (Eaton, HPE, many RFC 1628 devices)');
+    logger.dim('  3) Ticks (CyberPower - 1/100 second increments)');
+
+    const defaultUnitValue = snmpConfig.runtimeUnit === 'seconds'
+      ? 2
+      : snmpConfig.runtimeUnit === 'ticks'
+      ? 3
+      : snmpConfig.upsModel === 'cyberpower'
+      ? 3
+      : snmpConfig.upsModel === 'eaton'
+      ? 2
+      : 1;
+
+    const unitInput = await prompt(`Select runtime unit [${defaultUnitValue}]: `);
+    const unitValue = parseInt(unitInput, 10) || defaultUnitValue;
+
+    if (unitValue === 2) {
+      snmpConfig.runtimeUnit = 'seconds';
+    } else if (unitValue === 3) {
+      snmpConfig.runtimeUnit = 'ticks';
+    } else {
+      snmpConfig.runtimeUnit = 'minutes';
+    }
   }
 
   /**
@@ -1296,6 +1325,7 @@ export class UpsHandler {
       logger.logBoxLine(`SNMP Host: ${ups.snmp.host}:${ups.snmp.port}`);
       logger.logBoxLine(`SNMP Version: ${ups.snmp.version}`);
       logger.logBoxLine(`UPS Model: ${ups.snmp.upsModel}`);
+      logger.logBoxLine(`Runtime Unit: ${ups.snmp.runtimeUnit || 'auto'}`);
     }
 
     if (ups.groups && ups.groups.length > 0) {