fix(logging): add adaptive rate-limited DNS query logging, flush pending DNS logs on shutdown, and enhance email delivery logging

ts/classes.dcrouter.ts

@@ -212,6 +212,11 @@ export class DcRouter {
   public remoteIngressManager?: RemoteIngressManager;
   public tunnelManager?: TunnelManager;
 
+  // DNS query logging rate limiter state
+  private dnsLogWindow: number[] = [];
+  private dnsBatchCount: number = 0;
+  private dnsBatchTimer: ReturnType<typeof setTimeout> | null = null;
+
   // Certificate status tracking from SmartProxy events (keyed by domain)
   public certificateStatusMap = new Map<string, {
     status: 'valid' | 'failed';
@@ -855,6 +860,17 @@ export class DcRouter {
   public async stop() {
     logger.log('info', 'Stopping DcRouter services...');
 
+    // Flush pending DNS batch log
+    if (this.dnsBatchTimer) {
+      clearTimeout(this.dnsBatchTimer);
+      if (this.dnsBatchCount > 0) {
+        logger.log('info', `DNS: ${this.dnsBatchCount} queries processed (rate limited, final flush)`, { zone: 'dns' });
+      }
+      this.dnsBatchTimer = null;
+      this.dnsBatchCount = 0;
+      this.dnsLogWindow = [];
+    }
+
     await this.opsServer.stop();
 
     try {
@@ -1002,21 +1018,25 @@ export class DcRouter {
     // Start the server
     await this.emailServer.start();
 
-    // Wire delivery events to MetricsManager for time-series tracking
+    // Wire delivery events to MetricsManager and logger
     if (this.metricsManager && this.emailServer.deliverySystem) {
       this.emailServer.deliverySystem.on('deliveryStart', (item: any) => {
         this.metricsManager.trackEmailReceived(item?.from);
+        logger.log('info', `Email delivery started: ${item?.from} → ${item?.to}`, { zone: 'email' });
       });
       this.emailServer.deliverySystem.on('deliverySuccess', (item: any) => {
         this.metricsManager.trackEmailSent(item?.to);
+        logger.log('info', `Email delivered to ${item?.to}`, { zone: 'email' });
       });
       this.emailServer.deliverySystem.on('deliveryFailed', (item: any, error: any) => {
         this.metricsManager.trackEmailFailed(item?.to, error?.message);
+        logger.log('warn', `Email delivery failed to ${item?.to}: ${error?.message}`, { zone: 'email' });
       });
     }
     if (this.metricsManager && this.emailServer) {
       this.emailServer.on('bounceProcessed', () => {
         this.metricsManager.trackEmailBounced();
+        logger.log('warn', 'Email bounce processed', { zone: 'email' });
       });
     }
 
@@ -1203,9 +1223,18 @@ export class DcRouter {
     await this.dnsServer.start();
     logger.log('info', `DNS server started on UDP ${vmIpAddress}:53`);
 
-    // Wire DNS query events to MetricsManager for time-series tracking
+    // Wire DNS query events to MetricsManager and logger with adaptive rate limiting
     if (this.metricsManager && this.dnsServer) {
+      const flushDnsBatch = () => {
+        if (this.dnsBatchCount > 0) {
+          logger.log('info', `DNS: ${this.dnsBatchCount} queries processed (rate limited)`, { zone: 'dns' });
+          this.dnsBatchCount = 0;
+        }
+        this.dnsBatchTimer = null;
+      };
+
       this.dnsServer.on('query', (event: plugins.smartdns.dnsServerMod.IDnsQueryCompletedEvent) => {
+        // Metrics tracking
         for (const question of event.questions) {
           this.metricsManager.trackDnsQuery(
             question.type,
@@ -1215,6 +1244,21 @@ export class DcRouter {
             event.answered,
           );
         }
+
+        // Adaptive logging: individual logs up to 2/sec, then batch
+        const now = Date.now();
+        this.dnsLogWindow = this.dnsLogWindow.filter(t => now - t < 1000);
+
+        if (this.dnsLogWindow.length < 2) {
+          this.dnsLogWindow.push(now);
+          const summary = event.questions.map(q => `${q.type} ${q.name}`).join(', ');
+          logger.log('info', `DNS query: ${summary} (${event.responseTimeMs}ms, ${event.answered ? 'answered' : 'unanswered'})`, { zone: 'dns' });
+        } else {
+          this.dnsBatchCount++;
+          if (!this.dnsBatchTimer) {
+            this.dnsBatchTimer = setTimeout(flushDnsBatch, 5000);
+          }
+        }
       });
     }