fix: 统一文档解析文件格式校验

- 统一知识库和工作流支持格式并增加前后端上传拦截

- 拒绝 XLS 与伪装 XLSX，避免空内容解析成功

easyflow-ui-admin/app/src/locales/langs/en-US/documentCollection.json

@@ -79,7 +79,7 @@
     "progressUpload": "Progress of file upload",
     "fileSize": "File size",
     "batchUploadTitle": "Select files or drop them here",
-    "batchUploadDescription": "TXT, PDF, DOCX, MD, PPTX and XLSX. Up to 100MB per file and 1GB per folder.",
+    "batchUploadDescription": "Supported formats: {types}. Up to 100MB per file and 1GB per folder.",
     "batchUploadTip": "When upload completes, choose manual or automatic import.",
     "selectFolder": "Select Folder",
     "manualImport": "Manual Import",
@@ -95,8 +95,8 @@
     "singleFileLimit": "Each file must be no larger than 100MB",
     "folderSizeLimit": "The folder must be no larger than 1GB",
     "fileCountLimit": "A batch can contain up to 2000 files",
-    "noSupportedFiles": "No supported documents found",
-    "unsupportedSkipped": "Unsupported files were skipped",
+    "noSupportedFiles": "No supported documents found. Supported formats: {types}.",
+    "unsupportedSkipped": "Unsupported files were skipped. Supported formats: {types}.",
     "createBatchFailed": "Failed to create upload batch",
     "cancelBatchFailed": "Failed to cancel the upload batch. Please retry.",
     "uploadFailed": "Upload failed. Please retry.",