fix: multiple bug fixes

isolated users, db backup, weird disconnect issues for long voice sessions,

toju-app/src/app/infrastructure/realtime/signaling/signaling.manager.ts

@@ -17,8 +17,10 @@ import {
   SIGNALING_RECONNECT_MAX_DELAY_MS,
   SIGNALING_CONNECT_TIMEOUT_MS,
   STATE_HEARTBEAT_INTERVAL_MS,
+  SIGNALING_KEEPALIVE_INTERVAL_MS,
   SIGNALING_TYPE_IDENTIFY,
   SIGNALING_TYPE_JOIN_SERVER,
+  SIGNALING_TYPE_KEEPALIVE,
   SIGNALING_TYPE_VIEW_SERVER
 } from '../realtime.constants';
 
@@ -39,6 +41,7 @@ export class SignalingManager {
   private signalingReconnectAttempts = 0;
   private signalingReconnectTimer: ReturnType<typeof setTimeout> | null = null;
   private stateHeartbeatTimer: ReturnType<typeof setInterval> | null = null;
+  private lastKeepaliveSentAt = 0;
 
   /** Fires every heartbeat tick - the main service hooks this to broadcast state. */
   readonly heartbeatTick$ = new Subject<void>();
@@ -391,7 +394,11 @@ export class SignalingManager {
   /** Start the heartbeat interval that drives periodic state broadcasts. */
   private startHeartbeat(): void {
     this.stopHeartbeat();
-    this.stateHeartbeatTimer = setInterval(() => this.heartbeatTick$.next(), STATE_HEARTBEAT_INTERVAL_MS);
+    this.lastKeepaliveSentAt = Date.now();
+    this.stateHeartbeatTimer = setInterval(() => {
+      this.heartbeatTick$.next();
+      this.sendKeepaliveIfDue();
+    }, STATE_HEARTBEAT_INTERVAL_MS);
   }
 
   /** Stop the heartbeat interval. */
@@ -400,6 +407,28 @@ export class SignalingManager {
       clearInterval(this.stateHeartbeatTimer);
       this.stateHeartbeatTimer = null;
     }
+
+    this.lastKeepaliveSentAt = 0;
+  }
+
+  private sendKeepaliveIfDue(): void {
+    const now = Date.now();
+
+    if (now - this.lastKeepaliveSentAt < SIGNALING_KEEPALIVE_INTERVAL_MS) {
+      return;
+    }
+
+    this.lastKeepaliveSentAt = now;
+
+    try {
+      this.sendRawMessage({ type: SIGNALING_TYPE_KEEPALIVE });
+    } catch (error) {
+      this.logger.warn('[signaling] Failed to send signaling keepalive', {
+        error,
+        readyState: this.getSocketReadyStateLabel(),
+        url: this.lastSignalingUrl
+      });
+    }
   }
 
   /** Clean up all resources. */