refactor: 统一中文文案并简化组件结构，提升代码可读性

移除 chrome.i18n 后，将各功能页面、布局与工具模块的 UI 文案改为内联中文；
删除冗余注释与过度抽象（如 ToolCard、StatCard），精简 props 与状态管理；
同步优化 JsonTools、StorageCleaner、Timestamp、TestDataGenerator、Dashboard、
Base64Converter、RightClickRestorer、TextStatistics、TopBar、RouterProvider、
ThemeModeProvider 及生成器库与 utils 工具文件。

src/pages/TextStatistics/index.tsx

@@ -1,17 +1,24 @@
 import TextInputArea from '@/components/TextInputArea';
 import { formatBytes } from '@/utils/format';
-import StatCard from './components/StatCard';
+import { cn } from '@/lib/utils';
 import { useTextStatistics } from './useTextStatistics';
 
 export default function Index() {
   const { text, stats, setText } = useTextStatistics();
 
+  const statItems = [
+    { label: '字符数', value: stats.characters },
+    { label: '单词数', value: stats.words },
+    { label: '行数', value: stats.lines },
+    { label: '字节大小', value: formatBytes(stats.bytes) },
+  ];
+
   return (
     <div className="p-4 w-full space-y-4">
       <TextInputArea
         value={text}
         onChange={setText}
-        placeholder={'在此输入或粘贴文本...'}
+        placeholder="在此输入或粘贴文本..."
         minRows={10}
         maxRows={18}
         showClear={true}
@@ -19,10 +26,22 @@ export default function Index() {
       />
 
       <div className="grid grid-cols-2 md:grid-cols-4 gap-3">
-        <StatCard label="字符数" value={stats.characters} />
-        <StatCard label="单词数" value={stats.words} />
-        <StatCard label="行数" value={stats.lines} />
-        <StatCard label="字节大小" value={formatBytes(stats.bytes)} />
+        {statItems.map((item) => (
+          <div
+            key={item.label}
+            className={cn(
+              'flex flex-col justify-center items-center p-4 text-center rounded-xl border border-border bg-card shadow-sm text-card-foreground',
+              'hover:-translate-y-0.5 hover:shadow-md hover:border-primary/50 focus-within:ring-1 focus-within:ring-ring',
+            )}
+          >
+            <span className="text-xs font-medium text-muted-foreground tracking-wider mb-1 select-none">
+              {item.label}
+            </span>
+            <span className="font-mono text-lg md:text-2xl font-extrabold text-primary break-all tracking-tight leading-none tabular-nums select-all">
+              {item.value}
+            </span>
+          </div>
+        ))}
       </div>
     </div>
   );