feat: add notification events handling and MQTT integration

- Implemented notification event publishing with a new NotificationEventPublisher interface.
- Created a noopNotificationEventPublisher for testing purposes.
- Added functionality to publish notification created events via MQTT.
- Introduced a new stream event publisher for handling job logs and updates.
- Added database migration for popup_ads table.
- Created tests for notification events and popup ads functionality.
- Established MQTT connection and publishing helpers for event messages.

internal/service/catalog_mapper.go

@@ -1,7 +1,9 @@
 package service
 
-import appv1 "stream.api/internal/api/proto/app/v1"
-import "stream.api/internal/database/model"
+import (
+	appv1 "stream.api/internal/api/proto/app/v1"
+	"stream.api/internal/database/model"
+)
 
 func toProtoDomain(item *model.Domain) *appv1.Domain {
 	if item == nil {
@@ -33,6 +35,22 @@ func toProtoAdTemplate(item *model.AdTemplate) *appv1.AdTemplate {
 	}
 }
 
+func toProtoPopupAd(item *model.PopupAd) *appv1.PopupAd {
+	if item == nil {
+		return nil
+	}
+	return &appv1.PopupAd{
+		Id:                   item.ID,
+		Type:                 item.Type,
+		Label:                item.Label,
+		Value:                item.Value,
+		IsActive:             boolValue(item.IsActive),
+		MaxTriggersPerSession: func() int32 { if item.MaxTriggersPerSession != nil { return *item.MaxTriggersPerSession }; return 0 }(),
+		CreatedAt:            timeToProto(item.CreatedAt),
+		UpdatedAt:            timeToProto(item.UpdatedAt),
+	}
+}
+
 func toProtoPlayerConfig(item *model.PlayerConfig) *appv1.PlayerConfig {
 	if item == nil {
 		return nil