feat(purchase-transaction): 添加startImportStatusPolling方法

- 实现轮询检查导入任务状态
- 设置最多150次轮询(5分钟超时)
- 使用async/await处理异步请求
- 超时后自动停止轮询并提示用户
- 非PROCESSING状态时调用handleImportComplete处理结果

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

ruoyi-ui/src/views/ccdiPurchaseTransaction/index.vue

@@ -955,6 +955,34 @@ export default {
         this.$modal.msgError(response.msg);
       }
     },
+    /** 开始轮询导入状态 */
+    startImportStatusPolling(taskId) {
+      let pollCount = 0;
+      const maxPolls = 150; // 最多轮询150次(5分钟)
+
+      this.importPollingTimer = setInterval(async () => {
+        try {
+          pollCount++;
+
+          // 超时检查
+          if (pollCount > maxPolls) {
+            clearInterval(this.importPollingTimer);
+            this.$modal.msgWarning('导入任务处理超时,请联系管理员');
+            return;
+          }
+
+          const response = await getImportStatus(taskId);
+
+          if (response.data && response.data.status !== 'PROCESSING') {
+            clearInterval(this.importPollingTimer);
+            this.handleImportComplete(response.data);
+          }
+        } catch (error) {
+          clearInterval(this.importPollingTimer);
+          this.$modal.msgError('查询导入状态失败: ' + error.message);
+        }
+      }, 2000); // 每2秒轮询一次
+    },
     // 开始轮询导入状态
     startImportPolling(taskId) {
       const message = this.$message({