antinvestor_ui_notification

• Inbox channel/language filter chips now render in AdminEntityListPage's filters slot (requires antinvestor_ui_core ^0.5.1), so they sit below the breadcrumb instead of floating above the page header.

• NotificationSendScreen now surfaces failures that previously looked like a dead Send button: a snackbar appears when form validation fails (the invalid field may be scrolled out of view) and when the send RPC errors (mirroring the inline banner).

• Fix: the channel selector on NotificationSendScreen could never change selection — channels.first returned the previously selected channel (set insertion order), so taps on other chips were no-ops. The newly tapped channel is now selected.

• Added NotificationDashboardScreen (KPIs, channel mix, top failing templates).
• Added LanguageListScreen, LanguageEditScreen, EndUserInboxScreen, TemplateVariantMatrix.
• Added partitionIdProvider, tenancyScopeProvider, TenancyScope, languageSearchProvider, LanguageNotifier, notificationStatsProvider, NotificationStats. Search providers now re-key on the tenancy scope.
• Fixed: send screen now serializes payload as google.protobuf.Struct.
• Fixed: template save now persists variants via the request's data Struct.
• Changed: /notifications is now the dashboard; the inbox moved to /notifications/inbox.
• Changed: NotificationStatusBadge is a thin wrapper around StatusBadge.fromEnum.

(existing 0.1.x entries below)

• Migrate providers to Riverpod 3.x Notifier, fix lint warnings and deprecations

• Initial release
• Notification UI with inbox, compose, templates, delivery tracking, NotificationBadge widget