added the notify module

notify/notifications.go

@@ -0,0 +1,51 @@
+package notify
+
+// Notification represents a message that can be sent to subscribers.
+// Notifications contain metadata about the message (Level, Title),
+// the content (Message, Details), and an optional Action field for
+// custom application data.
+type Notification struct {
+	// Target specifies the subscriber ID to receive this notification.
+	// If empty when passed to NotifyAll(), the notification is broadcast
+	// to all subscribers. If set, only the targeted subscriber receives it.
+	Target Target
+
+	// Level indicates the notification severity (Success, Info, Warn, Error).
+	Level Level
+
+	// Title is a short summary of the notification.
+	Title string
+
+	// Message is the main notification content.
+	Message string
+
+	// Details contains additional information about the notification.
+	Details string
+
+	// Action is an optional field for custom application data.
+	// This can be used to attach contextual information, callback functions,
+	// URLs, or any other data needed by the notification handler.
+	Action any
+}
+
+// Target is a unique identifier for a subscriber.
+// Targets are automatically generated when a subscriber is created
+// using cryptographic random bytes (16 bytes, base64 URL-encoded).
+type Target string
+
+// Level represents the severity or type of a notification.
+type Level string
+
+const (
+	// LevelSuccess indicates a successful operation or positive outcome.
+	LevelSuccess Level = "success"
+
+	// LevelInfo indicates general informational messages.
+	LevelInfo Level = "info"
+
+	// LevelWarn indicates warnings that don't require immediate action.
+	LevelWarn Level = "warn"
+
+	// LevelError indicates errors that require attention.
+	LevelError Level = "error"
+)