feat: mail entity download

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

src/services/entityService.ts

@@ -2,7 +2,7 @@
  * Entity management service
  */
 
-import { transceivePost, transceiveStream } from './transceive';
+import { transceivePost, transceiveStream, transceiveDownload } from './transceive';
 import type {
   EntityFetchRequest,
   EntityFetchResponse,
@@ -27,6 +27,7 @@ import type {
   EntityListBulkRequest,
   EntityPatchResponse,
   EntityPatchRequest,
+  EntityDownloadRequest,
 } from '../types/entity';
 import { useIntegrationStore } from '@KTXC/stores/integrationStore';
 import { EntityObject } from '../models';
@@ -110,7 +111,7 @@ export const entityService = {
     
     // Convert response to EntityObject instances
     const list: Record<string, EntityObject> = {};
-    Object.entries(response).forEach(([identifier, entity]) => {
+    Object.entries(response).forEach(([, entity]) => {
       list[entity.identifier] = createEntityObject(entity);
     });
     
@@ -216,6 +217,16 @@ export const entityService = {
   async transmit(request: EntityTransmitRequest): Promise<EntityTransmitResponse> {
     return await transceivePost<EntityTransmitRequest, EntityTransmitResponse>('entity.transmit', request);
   },
+
+  /**
+   * Submit a browser-native attachment download request.
+   *
+   * The backend download endpoint is expected to honor the supplied selector
+   * and respond with an attachment payload rather than JSON.
+   */
+  download(request: EntityDownloadRequest): { transaction: string } {
+    return transceiveDownload<EntityDownloadRequest>('entity.download', request);
+  },
 };
 
 export default entityService;