- Bell opens a dropdown panel instead of a modal: Unread/All tabs, grouped
by day, type icons, relative times, click-through marks read, per-row
read/unread, mark all as read
- Unread badge refreshes every minute while the tab is visible
- Notifications page rebuilt on the same backend: search, type filter,
date range, read/unread toggles, proper empty states
- Hide notifications for clients/modules the user cannot access
- Normalise relative notification links so they work from /admin pages
- Remove the old notifications modal and dismiss handlers
