feat(home): 使用胶片盘图片导航图标

docs/plans/PROGRESS.md

@@ -1150,3 +1150,9 @@ $ flutter test
 - `AppRootTab.home` 未选中改为 `theaters_outlined`，选中改为 `theaters`。
 - 其余三个根导航图标、26 尺寸及白/灰颜色规则保持不变；测试断言同步。
 - 按当前流程未执行 analyze/test。
+
+## 2026-10-22 首页圆形胶片盘图标
+
+- `AppRootTab` 新增可选 `assetPath`，首页使用 `assets/icon/film_reel.png`。
+- 共享导航通过 `ColorFiltered + Image.asset` 按选中态着色，尺寸保持 26，缺图回退胶片 Material 图标。
+- 推荐、追剧、我的图标不变；素材与测试断言同步，按当前流程未执行 analyze/test。

lib/core/widgets/app_bottom_nav.dart

@@ -14,11 +14,13 @@ class AppBottomNavItem {
     required this.label,
     required this.onTap,
     this.selected = false,
+    this.assetPath,
   });
 
   final Key tabKey;
   final IconData icon;
   final IconData selectedIcon;
+  final String? assetPath;
   final String label;
   final VoidCallback onTap;
   final bool selected;
@@ -61,49 +63,66 @@ class _NavDestination extends StatelessWidget {
   final Color unselectedColor;
 
   @override
-  Widget build(BuildContext context) => Expanded(
+  Widget build(BuildContext context) {
-    child: Semantics(
+    final color = item.selected ? AppColors.navSelected : unselectedColor;
-      button: true,
+    final fallbackIcon = item.selected ? item.selectedIcon : item.icon;
-      selected: item.selected,
+    return Expanded(
-      label: item.label,
+      child: Semantics(
-      child: InkWell(
+        button: true,
-        key: item.tabKey,
+        selected: item.selected,
-        onTap: item.onTap,
+        label: item.label,
-        child: ConstrainedBox(
+        child: InkWell(
-          constraints: const BoxConstraints(minHeight: AppDimens.navHeight),
+          key: item.tabKey,
-          child: Column(
+          onTap: item.onTap,
-            mainAxisAlignment: MainAxisAlignment.center,
+          child: ConstrainedBox(
-            children: [
+            constraints: const BoxConstraints(minHeight: AppDimens.navHeight),
-              AnimatedScale(
+            child: Column(
-                duration: const Duration(milliseconds: 160),
+              mainAxisAlignment: MainAxisAlignment.center,
-                curve: Curves.easeOut,
+              children: [
-                scale: item.selected ? 1 : 0.96,
+                AnimatedScale(
-                child: Icon(
+                  duration: const Duration(milliseconds: 160),
-                  item.selected ? item.selectedIcon : item.icon,
+                  curve: Curves.easeOut,
-                  size: AppDimens.navIcon,
+                  scale: item.selected ? 1 : 0.96,
-                  color: item.selected
+                  child: item.assetPath == null
-                      ? AppColors.navSelected
+                      ? Icon(
-                      : unselectedColor,
+                          fallbackIcon,
+                          size: AppDimens.navIcon,
+                          color: color,
+                        )
+                      : ColorFiltered(
+                          colorFilter: ColorFilter.mode(color, BlendMode.srcIn),
+                          child: Image.asset(
+                            item.assetPath!,
+                            width: AppDimens.navIcon,
+                            height: AppDimens.navIcon,
+                            fit: BoxFit.contain,
+                            errorBuilder: (_, _, _) => Icon(
+                              item.icon,
+                              size: AppDimens.navIcon,
+                              color: color,
+                            ),
+                          ),
+                        ),
                 ),
-              ),
+                const SizedBox(height: AppDimens.navLabelGap),
-              const SizedBox(height: AppDimens.navLabelGap),
+                Text(
-              Text(
+                  item.label,
-                item.label,
+                  maxLines: 1,
-                maxLines: 1,
+                  overflow: TextOverflow.ellipsis,
-                overflow: TextOverflow.ellipsis,
+                  style: TextStyle(
-                style: TextStyle(
+                    fontSize: AppDimens.navLabel,
-                  fontSize: AppDimens.navLabel,
+                    fontWeight: item.selected
-                  fontWeight: item.selected ? FontWeight.w600 : FontWeight.w400,
+                        ? FontWeight.w600
-                  color: item.selected
+                        : FontWeight.w400,
-                      ? AppColors.navSelected
+                    color: color,
-                      : unselectedColor,
+                    letterSpacing: 0,
-                  letterSpacing: 0,
+                  ),
                 ),
-              ),
+              ],
-            ],
+            ),
           ),
         ),
       ),
-    ),
+    );
-  );
+  }
 }

lib/core/widgets/app_root_tab.dart

@@ -6,7 +6,16 @@ import '../../l10n/app_localizations.dart';
 import 'app_bottom_nav.dart';
 
 /// 客户端根导航的固定顺序。
-enum AppRootTab { home, recommend, following, mine }
+enum AppRootTab {
+  home(assetPath: 'assets/icon/film_reel.png'),
+  recommend(),
+  following(),
+  mine();
+
+  const AppRootTab({this.assetPath});
+
+  final String? assetPath;
+}
 
 extension AppRootTabUi on AppRootTab {
   Key get tabKey => switch (this) {
@@ -62,6 +71,7 @@ class AppRootBottomNav extends StatelessWidget {
             tabKey: tab.tabKey,
             icon: tab.icon,
             selectedIcon: tab.selectedIcon,
+            assetPath: tab.assetPath,
             label: tab.label(l10n),
             selected: tab == selected,
             onTap: () => onSelected(tab),

test/home/app_bottom_nav_test.dart

@@ -179,4 +179,29 @@ void main() {
       findsWidgets,
     );
   });
+
+  testWidgets('should_fallback_when_asset_icon_is_missing', (tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          bottomNavigationBar: AppBottomNav(
+            items: [
+              AppBottomNavItem(
+                tabKey: const Key('tab-home'),
+                icon: Icons.theaters_outlined,
+                selectedIcon: Icons.theaters,
+                assetPath: 'assets/icon/missing_film_reel.png',
+                label: 'Home',
+                selected: true,
+                onTap: () {},
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    expect(find.byIcon(Icons.theaters_outlined), findsOneWidget);
+  });
 }

test/home/home_nav_ui_test.dart

@@ -191,7 +191,7 @@ void main() {
     expect(
       find.descendant(
         of: find.byKey(const Key('tab-home')),
-        matching: find.byIcon(Icons.theaters),
+        matching: find.byType(Image),
       ),
       findsOneWidget,
     );
@@ -218,14 +218,28 @@ void main() {
     );
     expect(
       tester
-          .widget<Icon>(
+          .widget<ColorFiltered>(
             find.descendant(
               of: find.byKey(const Key('tab-home')),
-              matching: find.byIcon(Icons.theaters),
+              matching: find.byType(ColorFiltered),
             ),
           )
-          .color,
+          .colorFilter,
-      AppColors.navSelected,
+      const ColorFilter.mode(AppColors.navSelected, BlendMode.srcIn),
+    );
+    final selectedHomeImage = tester.widget<Image>(
+      find.descendant(
+        of: find.byKey(const Key('tab-home')),
+        matching: find.byType(Image),
+      ),
+    );
+    expect(
+      (selectedHomeImage.image as AssetImage).assetName,
+      'assets/icon/film_reel.png',
+    );
+    expect(
+      Size(selectedHomeImage.width!, selectedHomeImage.height!),
+      const Size.square(AppDimens.navIcon),
     );
 
     await tester.tap(find.byKey(const Key('tab-recommend')));
@@ -271,10 +285,21 @@ void main() {
     expect(
       find.descendant(
         of: find.byKey(const Key('tab-home')),
-        matching: find.byIcon(Icons.theaters_outlined),
+        matching: find.byType(Image),
       ),
       findsOneWidget,
     );
+    expect(
+      tester
+          .widget<ColorFiltered>(
+            find.descendant(
+              of: find.byKey(const Key('tab-home')),
+              matching: find.byType(ColorFiltered),
+            ),
+          )
+          .colorFilter,
+      const ColorFilter.mode(AppColors.navUnselected, BlendMode.srcIn),
+    );
   });
 
   testWidgets('should_map_four_tabs_to_home_recommend_following_and_me', (