Panel: de-dupe live notifications and expose recovery states on the board

Notification bell: the websocket stream was rendered with a plain filter, so
a stream replay after a reconnect surfaced — and counted — the same
notification twice, inflating the unread badge. De-duplicate by
notification_id (newest copy wins, arrival order preserved) and key the list
on the id instead of array index.

PM kanban: the board had no columns for the recovery states (paused,
needs-revision, awaiting-CEO-approval, cancelled), so a human had no way to
drive a wedged task into them from the UI. Add those columns; dragging a card
issues an admin status override, giving the CEO direct recovery from the board.

panel/src/components/notifications/notification-bell.tsx

@@ -58,7 +58,7 @@ export function NotificationBell() {
             <div className="space-y-2 max-h-64 overflow-y-auto">
               {notifications.slice(-10).reverse().map((notification, i) => (
                 <div
-                  key={i}
+                  key={notification.notification_id ?? `anon-${i}`}
                   className="p-2 rounded bg-muted hover:bg-muted/80 cursor-pointer"
                 >
                   <div className="flex items-center justify-between">