fix(ui): 下拉刷新刷新期间冻结下拉位移

test/core/app_pull_to_refresh_test.dart

@@ -9,9 +9,10 @@ import 'package:fruitshorts/core/widgets/app_pull_to_refresh.dart';
 import 'package:fruitshorts/l10n/app_localizations.dart';
 
 void main() {
-  testWidgets('should_hold_pull_offset_until_refresh_completes', (
+  testWidgets('should_freeze_pull_offset_until_refresh_completes', (
     tester,
   ) async {
+    expect(AppPullToRefresh.physics.parent, isA<ClampingScrollPhysics>());
     final refresh = Completer<void>();
     var calls = 0;
     await tester.pumpWidget(
@@ -66,13 +67,12 @@ void main() {
       AppColors.blue,
     );
     expect(calls, 1);
-    expect(_contentOffset(tester), greaterThan(56));
+    final releaseOffset = _contentOffset(tester);
+    expect(releaseOffset, greaterThan(56));
     expect(find.byType(CircularProgressIndicator), findsOneWidget);
 
-    await tester.pump(const Duration(milliseconds: 200));
-    expect(_contentOffset(tester), closeTo(56, 0.1));
     await tester.pump(const Duration(milliseconds: 300));
-    expect(_contentOffset(tester), closeTo(56, 0.1));
+    expect(_contentOffset(tester), closeTo(releaseOffset, 0.1));
 
     final duplicate = await tester.startGesture(
       tester.getCenter(find.byKey(const Key('pull-refresh-list'))),
@@ -81,7 +81,7 @@ void main() {
     await duplicate.up();
     await tester.pump();
     expect(calls, 1);
-    expect(_contentOffset(tester), closeTo(56, 0.1));
+    expect(_contentOffset(tester), closeTo(releaseOffset, 0.1));
 
     refresh.complete();
     await tester.pump();
@@ -90,6 +90,54 @@ void main() {
     expect(find.text('Refreshing…'), findsNothing);
     expect(find.text('Pull to refresh'), findsNothing);
   });
+
+  testWidgets('should_animate_back_when_released_below_threshold', (
+    tester,
+  ) async {
+    var calls = 0;
+    await tester.pumpWidget(
+      MaterialApp(
+        locale: const Locale('en'),
+        localizationsDelegates: AppLocalizations.localizationsDelegates,
+        supportedLocales: AppLocalizations.supportedLocales,
+        home: Scaffold(
+          body: AppPullToRefresh(
+            onRefresh: () async {
+              calls++;
+            },
+            child: ListView(
+              key: const Key('pull-refresh-list'),
+              physics: AppPullToRefresh.physics,
+              children: const [SizedBox(height: 1200)],
+            ),
+          ),
+        ),
+      ),
+    );
+
+    final list = find.byKey(const Key('pull-refresh-list'));
+    final gesture = await tester.startGesture(tester.getCenter(list));
+    await gesture.moveBy(const Offset(0, 30));
+    await tester.pump();
+    final releaseOffset = _contentOffset(tester);
+    expect(releaseOffset, greaterThan(0));
+    expect(releaseOffset, lessThan(56));
+    expect(find.text('Pull to refresh'), findsOneWidget);
+
+    await gesture.up();
+    await tester.pump();
+    expect(calls, 0);
+    expect(find.text('Refreshing…'), findsNothing);
+    expect(_contentOffset(tester), greaterThan(0));
+
+    await tester.pump(const Duration(milliseconds: 100));
+    expect(_contentOffset(tester), greaterThan(0));
+    expect(_contentOffset(tester), lessThan(releaseOffset));
+
+    await tester.pumpAndSettle();
+    expect(_contentOffset(tester), closeTo(0, 0.1));
+    expect(find.text('Pull to refresh'), findsNothing);
+  });
 }
 
 double _contentOffset(WidgetTester tester) {