fix: Connection Request fallback to IPv4 when CPE has IPv6-only URL

- device_record.ts: add lastRemoteIp field to store the CPE public IP
  from each Inform (X-Forwarded-For or TCP remote IP)
- cwmp_controller.ts: persist lastRemoteIp on every Inform alongside
  lastPeriodicInformAt (single  operation)
- device_service.ts: sendWakeOnWlan() now tries the original URL first
  (may be IPv6), then falls back to a rebuilt URL using lastRemoteIp
  (IPv4 public IP) if the ACS server has no IPv6 connectivity

app/controllers/cwmp_controller.ts

@@ -200,13 +200,14 @@ export default class CwmpController {
 
     logger.info({ events }, 'CWMP Inform events extracted')
 
-    // Track last periodic inform timestamp
+    // Track last periodic inform timestamp + last remote IP (used for Connection Request fallback)
     const normalizedEvents = events.map((e) => normalizeEventCode(e))
     const isPeriodic = normalizedEvents.some((e) => e === 'PERIODIC')
     const isBootstrap = normalizedEvents.some((e) => e === 'BOOTSTRAP')
-    if (isPeriodic || isBootstrap) {
-      await DeviceModel.updateOne({ identifier: hashId }, { $set: { lastPeriodicInformAt: new Date() } }).catch(() => {})
-    }
+    const cpeIpForStorage = (xForwardedFor || '').split(',')[0]?.trim() || remoteKey.split(':')[0]
+    const dbUpdate: Record<string, any> = { lastRemoteIp: cpeIpForStorage }
+    if (isPeriodic || isBootstrap) dbUpdate.lastPeriodicInformAt = new Date()
+    await DeviceModel.updateOne({ identifier: hashId }, { $set: dbUpdate }).catch(() => {})
 
     // Phase 12: Crash pattern detection
     const hasBoot = normalizedEvents.some((e) => e === 'BOOT')