feat(ui): 标题/菜单字号加大 + 顶部 textarea 简化

需求：左上角「数据治理工具」+ 菜单「身份证合规验证」字体都更大

改动 1 — MainLayout.vue：
- 标题 font-size 18px → 22px，logo icon 22px → 26px
- 菜单 font-size 17px → 20px，menu icon 19px → 22px
- 菜单项 height 52px → 56px（容纳更大字号）

改动 2 — IdCardTool.vue：
- 删除顶部「自由文本（与下方卡片互不联动）」提示
- 删除「清空」按钮
- 同步删 clearRuleText() 函数 + .idcard-page__head-bar/.head-hint 死代码
- 顶部仅保留一个干净的 textarea

build: 6.66s 通过

web2/src/layouts/MainLayout.vue

@@ -86,11 +86,11 @@ const activeMenu = computed(() => route.path)
   gap: 8px;
 }
 .layout-header__logo {
-  font-size: 22px;
+  font-size: 26px;
   color: #409eff;
 }
 .layout-header__title {
-  font-size: 18px;
+  font-size: 22px;
   font-weight: 600;
   color: #303133;
 }
@@ -114,12 +114,12 @@ const activeMenu = computed(() => route.path)
 }
 /* 菜单项字号加大 */
 .layout-menu :deep(.el-menu-item) {
-  font-size: 17px;
-  height: 52px;
-  line-height: 52px;
+  font-size: 20px;
+  height: 56px;
+  line-height: 56px;
 }
 .layout-menu :deep(.el-menu-item .el-icon) {
-  font-size: 19px;
+  font-size: 22px;
 }
 
 /* 内容区 */

web2/src/views/IdCardTool.vue

 <template>
   <div class="idcard-page">
-    <!-- 顶部独立 textarea：自由文本，与下方 5 张卡片互不联动 -->
     <el-card class="idcard-page__header" shadow="never">
-      <div class="idcard-page__head-bar">
-        <span class="idcard-page__head-hint">自由文本（与下方卡片互不联动）</span>
-        <el-button text type="primary" size="small" @click="clearRuleText">
-          清空
-        </el-button>
-      </div>
       <el-input
         v-model="ruleText"
         type="textarea"
@@ -657,19 +650,6 @@ watch(
   { flush: 'post' }
 )
 
-// 清空按钮
-function clearRuleText() {
-  ElMessageBox.confirm('确定清空顶部文本框？', '清空', {
-    confirmButtonText: '清空',
-    cancelButtonText: '取消',
-    type: 'warning',
-  })
-    .then(() => {
-      ruleText.value = ''
-      ElMessage.success('已清空')
-    })
-    .catch(() => {})
-}
 </script>
 
 <style scoped>
@@ -677,12 +657,6 @@ function clearRuleText() {
 .idcard-page__header {
   margin-bottom: 12px;
 }
-.idcard-page__head-bar {
-  display: flex;
-  align-items: center;
-  justify-content: space-between;
-  margin-bottom: 8px;
-}
 .idcard-page__head-hint {
   font-size: 12px;
   color: #909399;