feat(notifications): persistent read cursor + delivery history

notification_cursors table stores one read-cursor per user per tenant;
GET /v1/activity returns unreadCount + readAt, POST /v1/activity/read
persists the cursor. Reminder dispatches now append reminder.sent /
reminder.failed system events so delivery history reaches the feed.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/frontend/src/components/dashboard/notification-dropdown.tsx

@@ -26,7 +26,8 @@ export function NotificationDropdown(props: { bookings?: any[]; billing?: any; t
   const i18n = useI18n();
   const [open, setOpen] = createSignal(false);
 
-  const [activity] = createResource(
+  const [readAt, setReadAt] = createSignal<Date | null>(null);
+  const [activity, { refetch: refetchActivity }] = createResource(
     () => props.token?.(),
     async (bearer) => {
       if (!bearer) return [] as ActivityEvent[];
@@ -34,7 +35,9 @@ export function NotificationDropdown(props: { bookings?: any[]; billing?: any; t
         params: { query: { limit: 20 } },
         headers: { Authorization: `Bearer ${bearer}` },
       });
-      return (response.data?.events ?? []) as ActivityEvent[];
+      const data = response.data;
+      setReadAt(data?.readAt ? new Date(data.readAt) : null);
+      return (data?.events ?? []) as ActivityEvent[];
     },
     { initialValue: [] },
   );
@@ -52,6 +55,7 @@ export function NotificationDropdown(props: { bookings?: any[]; billing?: any; t
         const translated = i18n.t(key);
         return translated === key ? action : translated;
       };
+      const cursor = readAt();
       events.forEach((event) => {
         const actorSuffix = event.actorKind === "staff" && event.actorName ? ` · ${event.actorName}` : "";
         items.push({
@@ -60,7 +64,7 @@ export function NotificationDropdown(props: { bookings?: any[]; billing?: any; t
           title: actionLabel(event.action),
           message: `${event.summary}${actorSuffix}`,
           time: new Date(event.createdAt).toLocaleString(locale, { month: "short", day: "numeric", hour: "2-digit", minute: "2-digit" }),
-          read: false,
+          read: cursor != null && new Date(event.createdAt) <= cursor,
         });
       });
     } else {
@@ -113,7 +117,19 @@ export function NotificationDropdown(props: { bookings?: any[]; billing?: any; t
 
   const unreadCount = createMemo(() => filteredNotifications().filter((n) => !n.read).length);
 
-  const markAllRead = () => {
+  const markAllRead = async () => {
+    const bearer = props.token?.();
+    if (bearer) {
+      try {
+        const response = await (apiClient as any).POST("/v1/activity/read", {
+          headers: { Authorization: `Bearer ${bearer}` },
+        });
+        if (response.data?.readAt) setReadAt(new Date(response.data.readAt));
+        void refetchActivity();
+      } catch {
+        // Cursor write failed — fall back to local marks for this session.
+      }
+    }
     setReadIds(new Set(filteredNotifications().map((n) => n.id)));
   };
 

apps/frontend/src/providers/i18n-provider.tsx

@@ -367,6 +367,8 @@ const dictionaries = {
     "dashboard.activity.booking.rescheduled": "Rezervace přesunuta",
     "dashboard.activity.booking.moved": "Přesun na jinou lekci",
     "dashboard.activity.booking.promoted": "Povýšení z čekací listiny",
+    "dashboard.activity.reminder.sent": "Připomínka odeslána",
+    "dashboard.activity.reminder.failed": "Připomínka selhala",
     "dashboard.exportCsv": "Export CSV",
     "dashboard.demoBanner": "Demo režim",
     "dashboard.demoBannerDesc": "Prozkoumáte Bookra s ukázkovými daty. Pro plnou funkčnost se zaregistrujte.",
@@ -971,6 +973,8 @@ const dictionaries = {
     "dashboard.activity.booking.rescheduled": "Booking rescheduled",
     "dashboard.activity.booking.moved": "Moved to another session",
     "dashboard.activity.booking.promoted": "Promoted from waitlist",
+    "dashboard.activity.reminder.sent": "Reminder sent",
+    "dashboard.activity.reminder.failed": "Reminder failed",
     "dashboard.exportCsv": "Export CSV",
     "dashboard.demoBanner": "Demo mode",
     "dashboard.demoBannerDesc": "You're exploring Bookra with sample data. Register for full functionality.",