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

app/lib/application/pages/hub_page.dart

@@ -0,0 +1,53 @@
+import '../../database/database.dart';
+import '../../l10n/strings.dart';
+import '../../mews/document.dart';
+import 'mews_urls.dart';
+import 'page_blocks.dart';
+
+/// The hub names every page the client provides and says what each one holds,
+/// so the reader has somewhere to start. Its menu is the navigation, so it
+/// carries no strip of its own.
+Future<MewsPage> buildHubPage(
+  Uri url, {
+  required MewsDatabase db,
+  required Strings strings,
+}) async {
+  final bookmarks = await db.countBookmarks();
+  final sites = await db.countSubscriptions();
+  final visits = await db.countHistory();
+
+  return internalPage(
+    url: url,
+    title: strings.t('hub-title'),
+    body: [
+      HeadingBlock(1, [MewsText(strings.t('hub-title'))]),
+      itemList([
+        itemRow(
+          href: MewsUrls.bookmarks,
+          label: strings.t('nav-bookmarks'),
+          note: countText(strings, bookmarks,
+              none: 'count-bookmarks-none',
+              one: 'count-bookmarks-one',
+              many: 'count-bookmarks-many'),
+        ),
+        itemRow(
+          href: MewsUrls.subscriptions,
+          label: strings.t('nav-subscriptions'),
+          note: countText(strings, sites,
+              none: 'count-sites-none',
+              one: 'count-sites-one',
+              many: 'count-sites-many'),
+        ),
+        itemRow(
+          href: MewsUrls.history,
+          label: strings.t('nav-history'),
+          note: countText(strings, visits,
+              none: 'count-pages-none',
+              one: 'count-pages-one',
+              many: 'count-pages-many'),
+        ),
+        itemRow(href: MewsUrls.settings, label: strings.t('nav-settings')),
+      ]),
+    ],
+  );
+}