fix(runtime): prevent memory leaks and improve shutdown/stream handling across services

ts/classes.dcrouter.ts

@@ -534,6 +534,12 @@ export class DcRouter {
 
       // If we have DNS challenge handlers, create SmartAcme and wire to certProvisionFunction
       if (challengeHandlers.length > 0) {
+        // Stop old SmartAcme if it exists (e.g., during updateSmartProxyConfig)
+        if (this.smartAcme) {
+          await this.smartAcme.stop().catch(err =>
+            console.error('[DcRouter] Error stopping old SmartAcme:', err)
+          );
+        }
         this.smartAcme = new plugins.smartacme.SmartAcme({
           accountEmail: acmeConfig?.accountEmail || this.options.tls?.contactEmail || 'admin@example.com',
           certManager: new StorageBackedCertManager(this.storageManager),
@@ -944,6 +950,25 @@ export class DcRouter {
         await this.cacheDb.stop().catch(err => console.error('Error stopping CacheDb:', err));
       }
 
+      // Clear backoff cache in cert scheduler
+      if (this.certProvisionScheduler) {
+        this.certProvisionScheduler.clear();
+      }
+
+      // Allow GC of stopped services by nulling references
+      this.smartProxy = undefined;
+      this.emailServer = undefined;
+      this.dnsServer = undefined;
+      this.metricsManager = undefined;
+      this.cacheCleaner = undefined;
+      this.cacheDb = undefined;
+      this.tunnelManager = undefined;
+      this.radiusServer = undefined;
+      this.smartAcme = undefined;
+      this.certProvisionScheduler = undefined;
+      this.remoteIngressManager = undefined;
+      this.certificateStatusMap.clear();
+
       console.log('All DcRouter services stopped');
     } catch (error) {
       console.error('Error during DcRouter shutdown:', error);