feat(ui): 增加视觉 token 与统一导航

test/home/app_bottom_nav_test.dart

@@ -0,0 +1,46 @@
+// Author: fruit.com.cn
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:fruitshorts/core/theme/app_dimens.dart';
+import 'package:fruitshorts/core/widgets/app_bottom_nav.dart';
+
+void main() {
+  testWidgets('should_render_64_high_navigation_and_keep_item_keys', (
+    tester,
+  ) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          bottomNavigationBar: AppBottomNav(
+            items: [
+              AppBottomNavItem(
+                tabKey: const Key('tab-home'),
+                icon: Icons.movie_outlined,
+                selectedIcon: Icons.movie_rounded,
+                label: 'Home',
+                selected: true,
+                onTap: () {},
+              ),
+              AppBottomNavItem(
+                tabKey: const Key('tab-my'),
+                icon: Icons.person_outline_rounded,
+                selectedIcon: Icons.person_rounded,
+                label: 'Me',
+                onTap: () {},
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+
+    expect(find.byKey(const Key('tab-home')), findsOneWidget);
+    expect(find.byKey(const Key('tab-my')), findsOneWidget);
+    expect(find.text('Home'), findsOneWidget);
+    expect(
+      tester.getSize(find.byType(AppBottomNav)).height,
+      AppDimens.navHeight,
+    );
+  });
+}

test/theme/app_dimens_test.dart

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+// Author: fruit.com.cn
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:fruitshorts/core/theme/app_dimens.dart';
+
+void main() {
+  test('should_expose_the_k20_spacing_and_type_scale', () {
+    expect(AppDimens.pageHorizontal, 16);
+    expect(AppDimens.cardRadius, 16);
+    expect(AppDimens.innerRadius, 12);
+    expect(AppDimens.caption, 12);
+    expect(AppDimens.body, 14);
+    expect(AppDimens.listTitle, 15);
+    expect(AppDimens.sectionTitle, 16);
+    expect(AppDimens.pageTitle, 20);
+    expect(AppDimens.navLabel, 11);
+    expect(AppDimens.buttonHeight, 48);
+    expect(AppDimens.primaryButtonHeight, 52);
+    expect(AppDimens.tapTarget, 44);
+    expect(AppDimens.navHeight, 64);
+    expect(AppDimens.progressHeight, 4);
+  });
+}