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/database/model/popup_ads.gen.go

@@ -0,0 +1,30 @@
+// Code generated by gorm.io/gen. DO NOT EDIT.
+// Code generated by gorm.io/gen. DO NOT EDIT.
+// Code generated by gorm.io/gen. DO NOT EDIT.
+
+package model
+
+import (
+	"time"
+)
+
+const TableNamePopupAd = "popup_ads"
+
+// PopupAd mapped from table <popup_ads>
+type PopupAd struct {
+	ID                    string     `gorm:"column:id;type:uuid;primaryKey" json:"id"`
+	UserID                string     `gorm:"column:user_id;type:uuid;not null;index:idx_popup_ads_user_id,priority:1;index:idx_popup_ads_user_active,priority:2" json:"user_id"`
+	Type                  string     `gorm:"column:type;type:character varying(20);not null" json:"type"`
+	Label                 string     `gorm:"column:label;type:text;not null" json:"label"`
+	Value                 string     `gorm:"column:value;type:text;not null" json:"value"`
+	IsActive              *bool      `gorm:"column:is_active;type:boolean;not null;index:idx_popup_ads_user_active,priority:1;default:true" json:"is_active"`
+	MaxTriggersPerSession *int32     `gorm:"column:max_triggers_per_session;type:integer;not null;default:3" json:"max_triggers_per_session"`
+	CreatedAt             *time.Time `gorm:"column:created_at;type:timestamp with time zone;default:CURRENT_TIMESTAMP" json:"created_at"`
+	UpdatedAt             *time.Time `gorm:"column:updated_at;type:timestamp with time zone" json:"updated_at"`
+	Version               *int64     `gorm:"column:version;type:bigint;not null;default:1;version" json:"-"`
+}
+
+// TableName PopupAd's table name
+func (*PopupAd) TableName() string {
+	return TableNamePopupAd
+}