feat(recommend): 支持横向切换三个内容页

test/recommend/recommend_sections_test.dart

@@ -91,7 +91,7 @@ void main() {
     expect(player.homeMode, isTrue);
     expect(player.embedded, isTrue);
     expect(player.showHomeFeedHeader, isFalse);
-    expect(find.byType(PageView), findsOneWidget);
+    expect(find.byType(PageView), findsNWidgets(2));
     expect(find.byKey(const Key('recommend-section-hits')), findsNothing);
     expect(find.byType(AppBottomNav), findsOneWidget);
 
@@ -269,7 +269,7 @@ void main() {
     await tester.tap(find.byKey(const Key('recommend-tab-playlist')));
     await tester.pumpAndSettle();
     expect(find.byKey(const Key('recommend-section-hits')), findsOneWidget);
-    expect(find.byKey(const Key('recommend-feed-player')), findsNothing);
+    expect(find.byKey(const Key('recommend-feed-player')), findsOneWidget);
     expect(find.byType(AppBottomNav), findsOneWidget);
 
     await tester.tap(find.byKey(const Key('recommend-tab-all')));
@@ -278,6 +278,46 @@ void main() {
     expect(find.byKey(const Key('all-dramas-grid')), findsOneWidget);
   });
 
+  testWidgets('should_switch_inner_tabs_with_horizontal_page_swipes', (
+    tester,
+  ) async {
+    await _pumpRecommend(tester);
+    final pages = find.byKey(const Key('recommend-tab-page-view'));
+    final topNavBefore = tester.getRect(
+      find.byKey(const Key('recommend-top-nav')),
+    );
+
+    await tester.drag(pages, const Offset(-320, 0));
+    await tester.pumpAndSettle();
+    expect(find.byKey(const Key('recommend-section-hits')), findsOneWidget);
+    expect(find.byKey(const Key('recommend-feed-player')), findsOneWidget);
+    expect(
+      tester
+          .widget<Text>(
+            find.descendant(
+              of: find.byKey(const Key('recommend-tab-playlist')),
+              matching: find.text('Playlists'),
+            ),
+          )
+          .style
+          ?.color,
+      AppColors.textPrimary,
+    );
+    expect(
+      tester.getRect(find.byKey(const Key('recommend-top-nav'))),
+      topNavBefore,
+    );
+
+    await tester.drag(pages, const Offset(-320, 0));
+    await tester.pumpAndSettle();
+    expect(find.byKey(const Key('all-dramas-grid')), findsOneWidget);
+
+    await tester.drag(pages, const Offset(640, 0));
+    await tester.pumpAndSettle();
+    expect(find.byKey(const Key('recommend-feed-player')), findsOneWidget);
+    expect(find.byKey(const Key('recommend-tab-recommend')), findsOneWidget);
+  });
+
   testWidgets('should_open_standalone_player_from_title_and_watch_all', (
     tester,
   ) async {