- Update BackgroundTasksIndicator to display error sessions count alongside active sessions
- Include error sessions in App filter for notification banner visibility
- Add session cancellation for mission interviews on banner dismiss
- Add comprehensive test coverage for SessionNotificationBanner component
- Update useBackgroundSessions hook to expose error session counts
- Add SessionNotificationBanner to list awaiting_input AI sessions with type-specific labels/icons and resume or dismiss actions
- Integrate the banner into App project layout and wire resume handlers for planning, subtask, and mission interview sessions
- Add dismiss-all handling that clears all currently awaiting-input background sessions from the banner
- Style the banner with sticky placement, entry animation, responsive layout, and action button states
- Add component tests covering filtering, count rendering, resume/dismiss callbacks, type metadata, and local dismissal behavior
