docs: spec update - reuse existing topbar bell instead of new sidebar badge

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/superpowers/specs/2026-08-15-admin-purchase-notifications-design.md

@@ -39,16 +39,25 @@ status, is plain polling), so this has to be poll-based like the rest of the app
 - `FloatingNotificationsComponent` gets a click handler: navigate to `route` (if set)
   then dismiss.
 
-**Badge**
+**Badge — reuses existing topbar bell**
 
-- `unreadCount` signal (from `AdminOrderWatcherService`) rendered on the admin
-  sidebar's "Orders" nav item.
-- Visiting the orders list marks all currently-known orders as seen → badge resets to 0.
+`admin-layout.component.html:141-157` already has an unused bell icon +
+dropdown panel (currently hardcoded to always show "no notifications").
+Wire the watcher's data into it instead of adding a new indicator:
+
+- `unreadCount` signal (from `AdminOrderWatcherService`) rendered as a badge
+  on the bell icon (`admin-layout__icon-button`).
+- Opening the panel (`notificationsOpen()`, already wired to the bell click)
+  lists the unread new orders instead of the static "notificationsEmpty"
+  text.
+- Opening the panel marks all currently-known orders as seen → badge resets
+  to 0 (same trigger `AdminLayoutComponent.toggleNotifications()` already
+  has).
 
 **Click behavior**
 
 - Toast click → `/admin/orders/:id` (the new order's detail page).
-- Badge click → orders list.
+- Clicking an order row inside the bell panel → same, then closes the panel.
 
 ## Data flow