fix(flutter): 首页 feed 静默刷新与进度条细节

test/home/k28_a_navigation_test.dart

@@ -96,6 +96,32 @@ void main() {
     expect(find.text('Coming soon'), findsOneWidget);
   });
 
+  testWidgets('should_refresh_feed_without_blank_loading', (tester) async {
+    await _pumpApp(tester);
+
+    await tester.tap(find.byKey(const Key('home-feed-refresh')));
+    await tester.pump();
+
+    expect(find.byType(CircularProgressIndicator), findsNothing);
+    expect(find.byKey(const Key('home-feed-title')), findsOneWidget);
+    await tester.pumpAndSettle();
+    expect(find.byKey(const Key('home-feed-title')), findsOneWidget);
+  });
+
+  testWidgets('should_keep_feed_rail_above_bottom_panels', (tester) async {
+    await _pumpApp(tester);
+    final railTop = tester.getCenter(find.byKey(const Key('rail-save'))).dy;
+    final railBottom = tester
+        .getRect(find.byKey(const Key('rail-share')))
+        .bottom;
+    final infoTop = tester
+        .getRect(find.byKey(const Key('home-feed-series-meta')))
+        .top;
+
+    expect(railTop, greaterThan(844 * 0.35));
+    expect(railBottom, lessThanOrEqualTo(infoTop));
+  });
+
   testWidgets('should_restore_light_theme_after_leaving_feed_tab', (
     tester,
   ) async {