feat: add a hub for the client's own pages and gate mews:do action links

app/lib/application/pages/subscriptions_page.dart

@@ -0,0 +1,46 @@
+import '../../database/database.dart';
+import '../../l10n/strings.dart';
+import '../../mews/document.dart';
+import '../controllers/reader_settings_controller.dart' show LibraryController;
+import 'page_blocks.dart';
+
+Future<MewsPage> buildSubscriptionsPage(
+  Uri url, {
+  required MewsDatabase db,
+  required LibraryController library,
+  required Strings strings,
+}) async {
+  final sites = await db.allSubscriptions();
+  final title = strings.t('subscriptions-title');
+
+  return internalPage(
+    url: url,
+    title: title,
+    body: [
+      ...chrome(title: title, current: url, strings: strings),
+      if (sites.isEmpty)
+        ParagraphBlock([MewsText(strings.t('subscriptions-empty'))])
+      else
+        itemList([
+          for (final site in sites)
+            itemRow(
+              href: site.url,
+              label: site.title ?? site.url,
+              date: dayText(site.createdAt),
+              note: _unreadNote(library, strings, site.url),
+            ),
+        ]),
+    ],
+  );
+}
+
+/// The unread count for a site, or null when it has nothing new, so the row
+/// carries no empty line.
+String? _unreadNote(LibraryController library, Strings strings, String siteUrl) {
+  final count = library.newEntries.value[siteUrl]?.length ?? 0;
+  if (count == 0) return null;
+  return countText(strings, count,
+      none: 'count-unread-none',
+      one: 'count-unread-one',
+      many: 'count-unread-many');
+}