fix: upload ai table exports to oss

internal/httpapi/ai.go

@@ -443,11 +443,15 @@ func (a *API) aiTableAnalysisResource(w http.ResponseWriter, r *http.Request, p
 			writeStoreError(w, r, err)
 			return
 		}
-		fileName := aiTableExportFileName(item)
+		file, err := a.uploadAITableAnalysisExport(r.Context(), r, st, p, item)
+		if err != nil {
+			writeError(w, r, http.StatusServiceUnavailable, 30053, reasonAIProviderFailed, "ai export storage failed", nil)
+			return
+		}
 		writeSuccess(w, r, map[string]any{
-			"file_id":      "ai_export_" + recordID,
-			"file_name":    fileName,
-			"download_url": absoluteURL(r, "/v1/workbench/ai/table-analyses/"+recordID+"/export/download?format=docx"),
+			"file_id":      file.FileID,
+			"file_name":    file.FileName,
+			"download_url": file.DownloadURL,
 			"expires_at":   time.Now().UTC().Add(24 * time.Hour).Format(time.RFC3339Nano),
 		})
 		return