feat: backend service

gateway/internal/push/hub.go

@@ -273,6 +273,28 @@ func (h *Hub) RevokeDeviceSession(deviceSessionID string) {
 	}
 }
 
+// RevokeAllForUser closes every active subscription bound to userID,
+// regardless of device-session id. Used when backend emits a
+// SessionInvalidation that targets every session of a user.
+func (h *Hub) RevokeAllForUser(userID string) {
+	if h == nil {
+		return
+	}
+
+	userID = strings.TrimSpace(userID)
+	if userID == "" {
+		return
+	}
+
+	h.mu.RLock()
+	targets := cloneSubscriptions(h.byUser[userID])
+	h.mu.RUnlock()
+
+	for _, target := range targets {
+		h.unregister(target.id, ErrSubscriptionRevoked)
+	}
+}
+
 // Shutdown closes every active subscription because the gateway is shutting
 // down.
 func (h *Hub) Shutdown() {