feat(Dashboard): 重构仪表板功能组件和逻辑

- 新增 dashboardFeatures.ts 和 useDashboard.ts 文件，封装仪表板功能的解析和状态管理逻辑。
- 更新 Dashboard 组件，使用 useDashboard 钩子简化可见工具和最近使用工具的处理。
- 添加仪表板功能的单元测试，确保功能正确性。
- 更新 README.md，移除不再使用的 ToolCard 组件说明。

src/pages/Dashboard/__tests__/dashboardFeatures.test.ts

@@ -0,0 +1,49 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import * as featureConfig from '@/config/features';
+import { resolveDashboardFeatures } from '../dashboardFeatures';
+
+describe('resolveDashboardFeatures', () => {
+  beforeEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('应按 keys 顺序返回可见工具，并排除 dashboard', () => {
+    const items = resolveDashboardFeatures(['jwt', 'timestamp'], ['dashboard', 'timestamp', 'jwt']);
+
+    expect(items.map((item) => item.key)).toEqual(['jwt', 'timestamp']);
+    expect(items.map((item) => item.feature.label)).toEqual(['JWT 解析', '时间戳']);
+  });
+
+  it('缺少 themeColorKey 但有 icon 的工具仍应显示', () => {
+    const originalGetFeatureByKey = featureConfig.getFeatureByKey;
+    vi.spyOn(featureConfig, 'getFeatureByKey').mockImplementation((key) => {
+      const feature = originalGetFeatureByKey(key);
+      if (key === 'timestamp' && feature) {
+        return { ...feature, themeColorKey: undefined };
+      }
+      return feature;
+    });
+
+    const items = resolveDashboardFeatures(['timestamp'], ['dashboard', 'timestamp']);
+
+    expect(items.map((item) => item.key)).toEqual(['timestamp']);
+  });
+
+  it('应过滤不在 visiblePages 中的工具', () => {
+    const items = resolveDashboardFeatures(['jwt', 'timestamp'], ['dashboard', 'timestamp']);
+
+    expect(items.map((item) => item.key)).toEqual(['timestamp']);
+  });
+
+  it('visiblePages 无匹配工具时应返回空列表', () => {
+    const items = resolveDashboardFeatures(['jwt', 'timestamp'], ['dashboard']);
+
+    expect(items).toEqual([]);
+  });
+
+  it('应过滤缺少 icon 的工具', () => {
+    const items = resolveDashboardFeatures(['dashboard', 'timestamp'], ['dashboard', 'timestamp']);
+
+    expect(items.map((item) => item.key)).toEqual(['timestamp']);
+  });
+});