2b5223097f
Notification filtering: - lifecycle_hooks.py: only instance.error and instance.health_changed with status=running generate notifications. All other lifecycle events (created, started, stopped, restarted, deleted) are filtered out. - health_monitor.py: only error and unhealthy states generate notifications. Running/recovered state no longer creates info notifications. - _derive_title now maps instance.health_changed to "Container ready". Clear-all button: - Added dismiss_all() to NotificationService - Added DELETE /notifications endpoint for bulk dismiss - Frontend: clearAllNotifications API, clearAll in notification context, "Clear all" button in notification drawer alongside "Mark all as read" - Added CSS for .notification-clear-all with danger hover state - Updated notification-center tests Quality gates: pytest (21 passed), vitest (11 passed)