style: 全局 UI 主题皮肤重构与样式模块化

引入 Element Plus 主题定制和主题皮肤 composable，将全局
样式拆分为组件级独立 CSS 文件（侧边栏、顶栏、工作台等），
统一色彩变量和间距规范，重构所有视图和组件样式以适配新
主题系统，优化图表和知识图谱组件视觉表现，提取审计和差
旅报销相关子组件。

web/tests/documents-center-status-filter.test.mjs

@@ -149,11 +149,12 @@ test('documents center rows show NEW marker until the row is opened', () => {
   assert.doesNotMatch(documentsCenterStyles, /newDocumentPulse/)
 })
 
-test('documents center empty states stay emerald across all scope tabs', () => {
+test('documents center empty states follow theme tone across all scope tabs', () => {
   const emptyStateBlock = documentsCenterView.match(/const emptyState = computed\(\(\) => \{[\s\S]*?\n\}\)/)?.[0] || ''
 
-  assert.match(emptyStateBlock, /eyebrow: '申请单'[\s\S]*tone: 'emerald'/)
-  assert.match(emptyStateBlock, /title: filtered \? '没有符合当前条件的单据'[\s\S]*tone: 'emerald'/)
+  assert.match(emptyStateBlock, /eyebrow: '申请单'[\s\S]*tone: 'theme'/)
+  assert.match(emptyStateBlock, /title: filtered \? '没有符合当前条件的单据'[\s\S]*tone: 'theme'/)
+  assert.doesNotMatch(emptyStateBlock, /tone:\s*'emerald'/)
   assert.doesNotMatch(emptyStateBlock, /tone:\s*'sky'/)
   assert.doesNotMatch(emptyStateBlock, /tone:\s*'slate'/)
   assert.doesNotMatch(emptyStateBlock, /tone:\s*'amber'/)
@@ -199,8 +200,10 @@ test('documents center switches filter conditions by category tab', () => {
   assert.doesNotMatch(documentsCenterView, /class="status-filter-label"/)
   assert.match(
     documentsCenterView,
-    /watch\(activeFilterConfig, \(\) => \{[\s\S]*openFilterKey\.value = ''[\s\S]*datePopover\.value = false[\s\S]*pageSizeOpen\.value = false/
+    /watch\(activeFilterConfig, \(\) => \{[\s\S]*openFilterKey\.value = ''[\s\S]*datePopover\.value = false/
   )
+  assert.match(documentsCenterView, /<EnterpriseSelect v-model="pageSize"[\s\S]*:options="pageSizeOptions"/)
+  assert.doesNotMatch(documentsCenterView, /pageSizeOpen/)
 })
 
 test('documents center status dropdown derives labels and closes after selection', () => {