test: add notification channel routing tests (framework#1535)

[goravel-coder]

Summary

• Bumps goravel/framework to the channel-routing build (framework#1535) and switches example notifications from "mail"/"database" literals to the notification.ChannelMail/notification.ChannelDatabase constants.
• Adds a typed database route (RouteNotificationForDatabase) to the User model that takes precedence over the generic RouteNotificationFor fallback for the database channel.
• Adds feature coverage for typed-route precedence, empty-route errors (NotificationDatabaseEmptyRoute/NotificationMailEmptyRoute), and per-connection database delivery.

Why

Framework#1535 introduced typed notification routing: a DatabaseRoutable notifiable can declare RouteNotificationForDatabase(), which wins over the generic RouteNotificationFor fallback, and delivery fails with distinct empty-route errors when no route resolves. This branch upgrades the example to the new framework build, migrates example notifications to the exported channel constants, and implements the typed route on the User model so the example stays a faithful reference for the new API.

func (r *User) RouteNotificationFor(channel string) any {
	switch channel {
	case notification.ChannelMail:
		return r.Mail
	case notification.ChannelDatabase:
		return r.RouteNotificationForDatabase()
	default:
		return nil
	}
}

// RouteNotificationForDatabase implements contracts/notification.DatabaseRoutable:
// the type-safe database delivery route, preferred over RouteNotificationFor.
func (r *User) RouteNotificationForDatabase() string {
	return strconv.FormatUint(uint64(r.ID), 10)
}

The new tests pin down the routing semantics: the typed route is preferred when it returns a value, an empty typed route falls back to RouteNotificationFor, and both empty means delivery fails with the framework's empty-route error — so example behavior matches the framework contract exactly.