feat(client/notices): 通知页真实化+铃铛红点接 provider+进页清读+三类型标签六语

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01P9G7E3wmAYL9KeYCVZVsqu

client/lib/widgets/content_top_bar.dart

@@ -9,6 +9,7 @@ import '../pangolin_theme.dart';
 import '../state/app_providers.dart';
 import '../state/connection_provider.dart';
 import '../state/nodes_provider.dart';
+import '../state/notices_provider.dart';
 import 'notification_bell.dart';
 import 'pangolin_icons.dart';
 
@@ -63,7 +64,10 @@ class ContentTopBar extends ConsumerWidget {
         ),
         if (onBell != null) ...[
           const SizedBox(width: 12),
-          NotificationBell(onTap: onBell!, hasUnread: true),
+          NotificationBell(
+            onTap: onBell!,
+            hasUnread: (ref.watch(noticesProvider).valueOrNull?.unreadCount ?? 0) > 0,
+          ),
         ],
         if (showThemeToggle) ...[
           const SizedBox(width: 12),