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/src/views/TravelRequestDetailView.vue

@@ -241,11 +241,7 @@
                         <td class="expense-type col-type">
                           <template v-if="editingExpenseId === item.id">
                             <div class="cell-editor">
-                              <select v-model="expenseEditor.itemType" class="editor-select">
-                                <option v-for="option in expenseTypeOptions" :key="option.value" :value="option.value">
-                                  {{ option.label }}
-                                </option>
-                              </select>
+                              <EnterpriseSelect v-model="expenseEditor.itemType" class="editor-select" :options="expenseTypeOptions" size="small" />
                               <span>编辑费用项目</span>
                             </div>
                           </template>
@@ -763,58 +759,27 @@
       </div>
     </ConfirmDialog>
 
-    <ConfirmDialog
-      :open="deleteDialogOpen"
-      :badge="deleteActionLabel"
-      badge-tone="danger"
-      :title="deleteDialogTitle"
-      :description="deleteDialogDescription"
-      cancel-text="取消"
-      confirm-text="确认删除"
-      busy-text="删除中..."
-      confirm-tone="danger"
-      confirm-icon="mdi mdi-trash-can-outline"
-      :busy="deleteBusy"
-      @close="closeDeleteDialog"
-      @confirm="confirmDeleteRequest"
-    />
+    <TravelRequestDeleteDialog :open="deleteDialogOpen" :badge="deleteActionLabel" :title="deleteDialogTitle" :description="deleteDialogDescription" :busy="deleteBusy" @close="closeDeleteDialog" @confirm="confirmDeleteRequest" />
 
-    <ConfirmDialog
+    <TravelRequestApprovalDialog
       :open="approveConfirmDialogOpen"
       :badge="approvalConfirmBadge"
-      badge-tone="info"
       :title="approveConfirmTitle"
       :description="approvalConfirmDescription"
-      cancel-text="返回核对"
       :confirm-text="approveConfirmText"
       :busy-text="approveBusyText"
-      confirm-tone="primary"
-      confirm-icon="mdi mdi-check-circle-outline"
       :busy="approveBusy"
+      :document-no="request.documentNo || request.id"
+      :node="request.node"
+      :summary-label="approvalConfirmSummaryLabel"
+      :next-stage="approvalNextStage"
+      :opinion-title="approvalOpinionTitle"
+      :opinion="leaderOpinion"
       @close="closeApproveConfirmDialog"
       @confirm="confirmApproveRequest"
-    >
-      <div class="submit-confirm-summary" aria-label="领导审批通过摘要">
-        <div class="submit-confirm-row">
-          <span>单据编号</span>
-          <strong>{{ request.documentNo || request.id }}</strong>
-        </div>
-        <div class="submit-confirm-row">
-          <span>当前节点</span>
-          <strong>{{ request.node }}</strong>
-        </div>
-        <div class="submit-confirm-row">
-          <span>{{ approvalConfirmSummaryLabel }}</span>
-          <strong>{{ approvalNextStage }}</strong>
-        </div>
-        <div class="submit-confirm-row">
-          <span>{{ approvalOpinionTitle }}</span>
-          <strong>{{ leaderOpinion.trim() || '未填写' }}</strong>
-        </div>
-      </div>
-    </ConfirmDialog>
+    />
 
-    <ReturnReasonDialog
+    <TravelRequestReturnDialog
       :open="returnDialogOpen"
       :title="`确认退回 ${request.id} 吗？`"
       :description="returnDialogDescription"