Complete notification system API integration

[srgvg]

Context

Notification system is close to complete: 5 of 8 functions from notification.ts are used (63%). Three remaining functions need wiring to finish the feature.

API Functions to Wire Up

• createRule - Create notification rule
• deleteRule - Delete notification rule
• getHistory - Get notification history

Affected Files

• ui/src/api/notification.ts - API module (8 functions defined, 5 used)
• ui/src/stores/notifications.ts - Pinia store
• ui/src/pages/NotificationRulesPage.vue
• ui/src/pages/NotificationHistoryPage.vue

Acceptance Criteria

• Notification rule creation form works end-to-end
• Rule deletion with confirmation dialog
• Notification history page displays real data
• Error handling for all operations