feat(ui): update uxdocs Messages and Notifications

docs/ux/error-handling-loading-empty-states.md

@@ -74,16 +74,14 @@ A user has initiated an action, such as creating, updating, or deleting an item
 ### What To Do
 
 - Render as much as possible, keep app as a whole functional and responsive.
-- Give user feedback with as much detail as possible using Messages (use Notifications once NotificationManager is implemented).
+- Give user feedback with as much detail as possible using Messages or Notifications.
 - Do not interfere with or block other, potentially later initiated user actions.
 - Provide shortcuts/links to retry where and if possible.
 
 > **TODO:** Resolve open question: avoid blocking UI elements such as modals waiting for async action to complete, vs. keeping modal open with entered data when creation fails.
 
 > **TODO:** If async/transient state persists, show busy state ("Creating"). If too long, timeout, or positive result not to expect, change to static error state.
 
-> **TODO:** Concept and implement NotificationsManager.
-
 ## Validation Errors
 
 ### Examples

docs/ux/glossary.md

@@ -55,7 +55,7 @@ A dialog overlay that interrupts the current workflow to focus the user's attent
 A variant within a theme defining its visual appearance for a specific context or preference — such as light, dark, or high contrast. See also: Theme.
 
 **Notification**
-A transient, dynamic message that appears independently of the page layout — typically as a "toast" — to inform users of events occurring outside their current focus. Not yet available; requires the NotificationsManager component. See also: Message.
+A transient, dynamic message that appears independently of the page layout — typically as a "toast" — to inform users of events occurring outside their current focus. See also: Message.
 
 **Overflow Menu**
 A contextual menu triggered by a three-dot icon (⋮), used to surface additional actions for a specific item when displaying them inline would cause clutter or make them appear more important or often used than they actually are.

docs/ux/messages-and-notifications.md

@@ -60,15 +60,47 @@ disappears.
 
 ## Notifications
 
-> [!NOTE]
-> Toast Notifications are not yet available. The NotificationsManager component
-> required to display them is not yet implemented. Use Messages in the meantime.
-
 Notifications are transient, dynamic messages that appear independently of the
 page layout — typically as "toasts" in a fixed position on screen. Unlike
 Messages, they are not tied to a specific location in the UI and dismiss
 automatically or on user interaction.
 
-Notifications are suited for communicating events that occur asynchronously or
-outside the user's current focus — for example, the result of a background
-operation.
+Use Notifications to:
+
+- Confirm the result of a background or asynchronous operation
+- Communicate events that occur outside the user's current focus
+- Provide low-interruption feedback that does not require user action
+
+Do not use Notifications for persistent errors or warnings that require user
+attention or action. Use a [Message](#messages) placed close to the relevant
+content instead.
+
+### Toast and NotificationManager
+
+Juno provides two components for notifications:
+
+**`NotificationManager`** handles all notification lifecycle — timers,
+auto-dismiss, queuing, and screen position. Place it once near the root of your
+application.
+
+**`Toast`** is the presentational component rendered by `NotificationManager`.
+Do not use `Toast` directly — trigger notifications via the `toast()` API
+instead.
+
+Notifications use the same semantic variants as Messages: `info`, `success`,
+`warning`, `error`, and `danger`.
+
+### Auto-Dismiss
+
+Notifications auto-dismiss after a default timeout. Do not rely on auto-dismiss
+alone for `error` or `warning` notifications that require user action — these should stay until acknowledged or actively dismissed. For these cases, a [Message](#messages) may be the better choice.
+
+### Dismissible
+
+By default, notifications include a close button. Dismissibility can be
+configured globally on `NotificationManager` or overridden per notification.
+
+### Multiple Notifications
+
+`NotificationManager` supports displaying multiple notifications simultaneously.
+Additional notifications queue and appear as others close.

docs/ux/modals.md

@@ -26,7 +26,7 @@ A Modal is likely not the most suitable solution if the task…
 - can easily be completed at any time inline in the natural flow of the current page or view
 - contains excessively large or long content that would be better handled on a separate page or view
 - is triggered by a parent task that already runs in a Modal (never stack Modals)
-- is not a task but a simple, non-essential notification or message — use Message or Notification (TBD) instead
+- is not a task but a simple, non-essential notification or message — use Message or Notification instead
 - requires many different action buttons at the bottom. Consider using a menu of options and then using a Modal only to confirm the selected action.
 
 ## Modal Anatomy