feat(home): 顶部导航随翻页联动并把推荐更名为精选

lib/core/widgets/animated_nav_label.dart

@@ -0,0 +1,71 @@
+// Author: fruit.com.cn
+// 职责：固定顶部导航文字排版，以绘制缩放和颜色插值实现选中切换。
+import 'package:flutter/material.dart';
+
+import '../theme/app_colors.dart';
+import '../theme/app_dimens.dart';
+
+const double _inactiveScale = 0.9;
+
+/// 保留最大字号、固定字重与占位，避免选中动画触发相邻标签重新布局。
+class AnimatedNavLabel extends StatelessWidget {
+  /// [style] 指定选中态字号与颜色；字重固定，未指定时默认加粗。
+  const AnimatedNavLabel({
+    super.key,
+    required this.label,
+    required this.selected,
+    required this.style,
+    this.alignment = Alignment.bottomCenter,
+    this.selectionProgress,
+    this.inactiveColor = AppColors.textTabInactive,
+  });
+
+  final String label;
+  final bool selected;
+  final TextStyle style;
+  final Alignment alignment;
+
+  /// 未选中文字颜色；默认保持通用导航原有灰色。
+  final Color inactiveColor;
+
+  /// 页面拖动时直接使用连续进度，避免再叠加一层延迟动画。
+  final double? selectionProgress;
+
+  @override
+  Widget build(BuildContext context) {
+    final target = selected ? 1.0 : 0.0;
+    final reduceMotion = MediaQuery.disableAnimationsOf(context);
+    return Semantics(
+      selected: selected,
+      child: selectionProgress != null
+          ? _label(selectionProgress!.clamp(0.0, 1.0))
+          : TweenAnimationBuilder<double>(
+              tween: Tween(begin: target, end: target),
+              duration: reduceMotion
+                  ? Duration.zero
+                  : AppDimens.homePrimaryTabAnimationDuration,
+              curve: Curves.easeOut,
+              builder: (context, progress, _) => _label(progress),
+            ),
+    );
+  }
+
+  Widget _label(double progress) => Transform.scale(
+    scale: _inactiveScale + (1 - _inactiveScale) * progress,
+    alignment: alignment,
+    child: Text(
+      label,
+      maxLines: 1,
+      textAlign: TextAlign.left,
+      style: style.copyWith(
+        fontWeight: style.fontWeight ?? FontWeight.w700,
+        letterSpacing: 0,
+        color: Color.lerp(
+          inactiveColor,
+          style.color ?? AppColors.textPrimary,
+          progress,
+        ),
+      ),
+    ),
+  );
+}

lib/core/widgets/app_root_tab.dart

@@ -25,14 +25,14 @@ extension AppRootTabUi on AppRootTab {
 
   IconData get icon => switch (this) {
     AppRootTab.home => Icons.home_outlined,
-    AppRootTab.recommend => Icons.celebration_outlined,
+    AppRootTab.recommend => Icons.smart_display_outlined,
     AppRootTab.following => Icons.bookmark_border_rounded,
     AppRootTab.mine => Icons.person_outline_rounded,
   };
 
   IconData get selectedIcon => switch (this) {
     AppRootTab.home => Icons.home_rounded,
-    AppRootTab.recommend => Icons.celebration_rounded,
+    AppRootTab.recommend => Icons.smart_display_rounded,
     AppRootTab.following => Icons.bookmark_rounded,
     AppRootTab.mine => Icons.person_rounded,
   };